Metal Halide Perovskite Solar Cells: Sources of High Efficiency, Stability Bottlenecks, and Experimental Decision Logic

Introduction

Perovskite is not a single substance, but a class of materials with specific crystal-structure characteristics. In the photovoltaic field, the term “perovskite” usually refers to metal halide perovskites. These materials are composed of organic or inorganic cations, metal ions, and halide ions, and are commonly used as light-absorbing layers in solar cells. The U.S. Department of Energy also notes that the perovskites commonly discussed in photovoltaics should be more accurately referred to as metal halide perovskites, which are different from many oxide perovskite materials.

These materials have attracted attention for two core reasons:

Core question	Key answer
Why can they achieve high efficiency?	Strong light absorption in thin layers, tunable bandgaps, relatively good charge-transport properties, and suitability for forming tandem cells with silicon and other materials
Why are they difficult to stabilize?	Moisture, oxygen, heat, light, voltage bias, ion migration, interfacial reactions, and insufficient encapsulation can jointly trigger degradation

1. What Are Metal Halide Perovskites?

Metal halide perovskites can usually be understood in terms of the A site—B site—X site. The A site is generally occupied by organic or inorganic cations, the B site by metal ions, and the X site by halide ions such as iodide, bromide, and chloride.

Structural position	Common composition	Main influence
A site	Methylammonium, formamidinium, cesium, and other cations	Affects lattice size, phase stability, and crystallization behavior
B site	Lead, tin, and other metal ions	Affects bandgap, light absorption, charge transport, and environmental risks
X site	Iodide, bromide, chloride, and other halide ions	Affects absorption range, bandgap, crystal phase, and defect behavior

Three concepts should be distinguished first:

Concept	Explanation
Perovskite structure	Refers to a class of crystal structures, not a single fixed compound
Oxide perovskites	Mostly used in electronic ceramics, ferroelectrics, dielectric materials, catalysis, and related fields
Metal halide perovskites	Commonly used in photovoltaics, light emission, and detection; this article focuses on solar cells

2. Why Can Perovskite Solar Cells Achieve High Efficiency?

Metal halide perovskites can function as highly efficient light-absorbing layers mainly because of four material characteristics. According to the U.S. Department of Energy webpage, the efficiency of small-area perovskite solar cells has increased from about 3% in 2009 to more than 26%, while perovskite/silicon tandem cells have reached efficiencies approaching 34%; specific certified records will continue to be updated as new test results become available.

Source of high efficiency	Significance for solar cells
Strong light absorption	A relatively thin absorber layer can absorb a large amount of sunlight
Tunable bandgap	The absorption range can be adjusted through composition control, making the material suitable for both single-junction and tandem cells
Long carrier diffusion length, allowing charges to be effectively separated and collected	Photogenerated electrons and holes have the opportunity to be efficiently extracted
A certain degree of defect tolerance	Some defects have a relatively limited impact on performance, which is beneficial for low-temperature thin-film fabrication

“Defect tolerance” does not mean that defects are unimportant. Deep-level defects, surface defects, grain-boundary defects, and interfacial defects can still cause non-radiative recombination, lowering the open-circuit voltage, fill factor, and long-term stability.

3. How Composition Control Affects Bandgap, Film Formation, and Stability

Composition control in perovskites involves balancing bandgap, phase stability, crystallization behavior, defect density, and environmental risks.

Control position	Common direction	Main objective	Issues requiring attention
A site	Methylammonium, formamidinium, cesium, and mixed cations	Adjust lattice stability, phase stability, and crystallization process	Single-component systems may face thermal-stability, phase-stability, or film-formation issues
B site	Lead, tin, and mixed lead–tin systems	Tune bandgap, light absorption, and charge transport	Lead involves environmental risks; in tin-based systems, Sn²⁺ is easily oxidized to Sn⁴⁺, so tin vacancies, defects, and leakage current need attention
X site	Iodide, bromide, chloride, and mixed halides	Adjust absorption range and bandgap	Mixed-halide systems require attention to light-induced phase separation and stability
Dimensional structure	Three-dimensional, two-dimensional, quasi-two-dimensional, and two-dimensional/three-dimensional interfaces	Adjust surface stability, interfacial recombination, and tolerance to moisture and oxygen	Excessive insulating organic layers may hinder charge transport

In experiments, whether the composition is reasonable should first be judged by asking three questions:

Question	Key point for judgment
Does the bandgap match the target device?	Single-junction cells, wide-bandgap top cells in tandems, and low-bandgap bottom cells in tandems have different requirements
Can the film readily form the target phase?	Phase purity, crystallization integrity, and surface coverage should be confirmed first
Is the main stability weakness clear?	Identify whether moisture/oxygen, heat, light, bias, or interfacial reactions are the most prominent issue

4. From Precursors to the Absorber Layer: How Film Quality Affects Efficiency and Reproducibility

Perovskite solar cells are usually not made from bulk crystals. Instead, thin films are formed from precursor salts, solvents, and deposition processes. The U.S. Department of Energy’s description of the fabrication process includes mixing precursor salts, depositing an ultrathin perovskite layer, heating to form the film, and then depositing other functional layers.

Experimental step	Main influence	Priority observations
Precursor ratio	Target phase formation, residual salt content, defect level, and crystallization pathway	Whether the solution is clear and whether the ratio is reproducible
Solvent system	Solubility, evaporation rate, formation of coordination intermediates, and crystallization rate	Whether the wet film is uniform and whether premature crystallization occurs
Deposition method	Film thickness, coverage, surface uniformity, and local defects	Whether pinholes, streaks, or edge accumulation appear
Annealing conditions	Phase transformation, grain growth, removal of residual solvent, and film compactness	Whether the film color is uniform and whether the crystal phase is stable
Substrate cleaning	Interfacial wetting, film continuity, and contact quality with the underlying layer	Whether dewetting, shrinkage holes, or local non-film-forming regions appear
Environmental humidity	Crystallization process, water participation in reactions, defect formation, and subsequent degradation risk	Whether the same formulation shows clear differences under different humidity conditions

Common characterization methods and the specific questions they address:

Question to confirm	Applicable method
Whether the target crystal phase has formed	X-ray diffraction
Whether the absorption range matches the design	Ultraviolet–visible absorption spectroscopy
Whether defect-related recombination is serious	Photoluminescence and time-resolved photoluminescence
Whether the film provides continuous coverage	Optical microscopy and scanning electron microscopy
Whether the surface is excessively rough	Atomic force microscopy
Whether the elemental distribution deviates from the design	Surface-composition and depth-profile composition analysis

When device efficiency is low, the first step should not be to directly replace the transport layer or additives. Instead, one should confirm whether the perovskite layer has formed the correct phase, provides continuous coverage, has few pinholes, and contains a controllable amount of residual phases.

5. From the Absorber Layer to the Complete Device: How Structural Design Affects Charge Collection and Efficiency

The main role of the perovskite absorber layer is to absorb light and generate electrons and holes. To produce an effective current, these electrons and holes must not recombine inside the absorber layer or at interfaces; instead, they need to be directed toward different electrodes. The electron transport layer receives and transports electrons while suppressing holes from entering the electron side. The hole transport layer receives and transports holes while suppressing electrons from entering the hole side. The metal electrode and transparent conductive substrate then connect these charges to the external circuit.

Therefore, the efficiency of a perovskite solar cell depends not only on the absorber layer itself, but also on whether the energy levels of the transport layers are well matched, whether the interfacial contact is good, whether charge extraction is smooth, and whether the electrode is stable.

Device layer	Main function	Common issues
Transparent conductive substrate	Transmits light and collects charge	Surface contamination, roughness, and non-uniform conductivity
Electron transport layer	Selectively extracts electrons and suppresses reverse recombination	Energy-level mismatch, transport resistance, and interfacial defects
Perovskite absorber layer	Absorbs light and generates electrons and holes	Pinholes, residual phases, ion migration, and defect recombination
Hole transport layer	Selectively extracts holes	Moisture absorption by dopants, insufficient thermal stability, and interfacial reactions
Metal electrode	Collects current and completes the external circuit connection	Metal diffusion, halide reactions, and contact degradation

6. How Performance Data Correspond to Experimental Problems

For perovskite solar cells, the highest efficiency alone is not enough. Open-circuit voltage, short-circuit current density, fill factor, hysteresis, steady-state output, and external quantum efficiency each correspond to different problems.

Experimental observation	Priority check	Common cause direction
Low open-circuit voltage	Defect recombination and interfacial recombination	Surface defects, grain-boundary defects, energy-level mismatch, and transport-layer interfacial losses
Low short-circuit current density	Light absorption and charge extraction	Insufficient film thickness, mismatched absorption range, pinholes, and transport-layer blocking
Low fill factor	Resistance and interfacial contact	High series resistance, leakage current, poor interfacial contact, and insufficient transport-layer conductivity
Clear difference between forward and reverse scans	Hysteresis and ion migration	Ion migration, interfacial charge accumulation, and differences in test preconditioning
Steady-state output lower than scan efficiency	Instability at the actual operating point	Ion redistribution, interfacial charge accumulation, and light-induced degradation
Large batch-to-batch variation	Film formation and interfacial reproducibility	Solution aging, humidity fluctuation, substrate cleaning, and annealing deviations

Reliable data should include at least the following:

1. Forward and reverse scan results;

2. Steady-state power output;

3. External quantum efficiency and integrated current cross-check;

4. Statistical results from multiple devices;

5. Clear test conditions and device area;

6. Stability test conditions and retention rate.

7. Stability Bottlenecks: How Materials, Interfaces, and Encapsulation Jointly Affect Device Lifetime

The stability problem of metal halide perovskite solar cells cannot be attributed solely to moisture sensitivity. During operation and storage, real devices are simultaneously affected by moisture, oxygen, heat, light, and operating bias. The perovskite absorber layer itself may undergo phase transitions, decomposition, or ion migration; the interface between the transport layer and perovskite may suffer intensified recombination or chemical reactions; the metal electrode may also diffuse and, together with halide migration, trigger interfacial degradation. If encapsulation cannot effectively block moisture and oxygen ingress, external environmental stress will continuously amplify these failure processes.

Therefore, the stability of perovskite devices is not a single-material problem. It is a comprehensive reliability issue involving the absorber layer, transport layers, electrodes, and encapsulation under the combined effects of light, heat, moisture/oxygen, and electric field. Before commercialization, the key challenges to address are precisely efficiency retention under long-term operating conditions, interfacial stability, and encapsulation reliability.

Failure source	Possible result	Experimental manifestation
Moisture	Hydration, decomposition, or phase changes of the absorber layer	Film color change, decreased absorption, and rapid efficiency loss
Oxygen	Defect changes or oxidation processes jointly induced with light	Accelerated degradation under illumination in air
Thermal stress	Phase transitions, ion diffusion, and interfacial reactions	Decreased voltage and fill factor after high-temperature exposure
Light	Light-induced defect changes or ion migration; in mixed-halide systems, possible halide phase separation	Output fluctuation under continuous illumination
Voltage bias	Ion accumulation at interfaces, altering the built-in electric field	Enhanced hysteresis and decreased steady-state output
Electrode reactions	Metal diffusion, halide corrosion, and contact degradation	Increased series resistance and irreversible efficiency loss
Insufficient encapsulation	Continuous ingress of external moisture and oxygen into the device	Large differences between storage stability and operational stability

Stability improvement needs to consider the following directions simultaneously:

Control direction	Target effect
Composition design	Improve phase stability and reduce the proportion of easily decomposable components
Crystallization control	Reduce defect density and the number of pinholes
Surface passivation	Reduce non-radiative recombination and surface reaction sites
Interface modification	Improve energy-level matching and interfacial chemical stability
Transport-layer replacement	Reduce risks related to moisture absorption, diffusion, and thermal failure
Electrode and encapsulation	Reduce metal diffusion, moisture/oxygen ingress, and edge failure

8. From Small-Area Devices to Modules: Which Performance and Process Issues Are Amplified?

Small-area perovskite devices are usually fabricated under controlled conditions. Because the film area is small, the defect area is limited, and the current transport path is short, high efficiency can be achieved more readily. After scaling up to modules, the absorber layer, transport layers, and electrodes must remain uniform over a larger area. Multiple sub-cells also need to be connected in series through scribing and interconnection. At this stage, local pinholes, film-thickness fluctuations, non-uniform interfacial contact, scribing damage, moisture/oxygen ingress from encapsulation edges, and current mismatch between sub-cells can all be amplified into module efficiency loss or long-term degradation.

Therefore, module scale-up is not simply making small-area devices larger. It simultaneously tests large-area film formation, interlayer interfaces, series interconnection, encapsulation reliability, and long-term validation. The U.S. Department of Energy has also pointed out that small-area perovskite devices have already shown competitive efficiencies, but the stable fabrication of high-efficiency devices over large areas remains challenging; large-scale manufacturing requires reproducible preparation of uniform, high-performance perovskite materials under manufacturing environments.

Focus for small-area devices	Additional issue after scale-up
Highest efficiency of a single device	Average efficiency and uniformity over a large area
Spin coating or small-area coating	Scalable processes such as slot-die coating, blade coating, spray coating, and evaporation
Single-point current–voltage testing	Module series losses and area-normalized efficiency
Small-cell encapsulation	Edge sealing, interlayer adhesion, and long-term moisture protection
Short-term laboratory stability	Outdoor illumination, temperature cycling, damp heat, and bias acting together
Single-batch results	Multi-batch reproducibility and third-party validation

9. In What Order Should a New Perovskite System Be Evaluated Experimentally?

For a new metal halide perovskite system, the evaluation sequence should not begin with the highest single-device efficiency. Instead, the material target should first be confirmed, followed by stepwise examination of the film, interfaces, device performance, and stability. This helps avoid misjudging a film-formation problem as a transport-layer problem, and also avoids discussing scale-up too early before the results are stable.

Step	Question to answer first	Key checks
1	Are the target device and bandgap requirement clear?	Single-junction cell, top cell in a tandem, bottom cell in a tandem, or reference device; whether the target absorption range and bandgap are clear
2	Does the material composition match the target performance?	Whether the A site, B site, and X site match the target bandgap, phase stability, and film-formation requirements
3	Does the film form the target crystal phase?	Crystal phase, absorption spectrum, film coverage, residual phases, and phase stability
4	Does the film quality meet the requirements for device fabrication?	Film-thickness uniformity, pinholes, streaks, grain state, surface roughness, and substrate wetting
5	Have recombination and defects become the main loss source?	Photoluminescence, time-resolved photoluminescence, grain-boundary defects, surface defects, and interfacial recombination
6	Are the transport layers and interfaces well matched?	Energy-level matching, charge selectivity, interfacial contact, wettability, and chemical stability
7	Where do the main device performance losses come from?	Open-circuit voltage, short-circuit current density, fill factor, hysteresis, and steady-state power output
8	Where is the main stability weakness?	Moisture/oxygen, heat, light, bias, ion migration, electrode reactions, and encapsulation reliability
9	Are the results reproducible?	Multi-device statistics, external quantum efficiency, current cross-check, steady-state output, and consistency of test conditions
10	Is there a basis for scale-up validation?	Large-area film uniformity, process window, module interconnection, encapsulation edges, and long-term operational stability

10. Product Selection Navigation for Metal Halide Perovskite Solar Cell–Related Products（Product Tables 1–6）

Research or experimental goal	Recommended table to consult first	Why consult this table first	Suggested related table(s)	Navigation notes
Build perovskite precursor solutions and film-forming conditions	Table 1	Table 1 focuses on main precursor solvents, coordinating solvents, and antisolvents, making it suitable for first establishing the basic conditions for dissolution, coordination, evaporation, and crystallization control	Tables 2 and 3	First determine the solvent system, then combine A-site cations, lead halide salts, or tin halide salts to build the absorber-layer formulation
Compare how different film-formation routes affect thin-film morphology	Table 1	Film uniformity, pinholes, grain formation, and intermediate-phase formation are closely related to the solvent system	Table 4	If film coverage is uneven or the grain state is unsatisfactory, Table 4 can be consulted to examine crystallization modifiers and surface passivation materials
Design mixed-cation systems involving methylammonium, formamidinium, and cesium	Table 2	Table 2 lists methylammonium salts, formamidinium salts, and cesium salts, which can be used to regulate the lattice, phase stability, and crystallization behavior	Tables 3 and 4	First determine the A-site composition, then combine it with the ratios of lead halides or tin halides; passivation materials can subsequently be used to reduce surface recombination
Adjust the iodide/bromide ratio to design absorber layers with different bandgaps	Table 2	Table 2 provides A-site precursors as iodide and bromide sources, suitable for designing iodide-based, bromide-based, and mixed iodide–bromide systems	Tables 3 and 6	If the target is a wide-bandgap or all-inorganic system, Table 3 can be used to select lead halides, while Table 6 can be used to establish material references
Construct lead-based perovskite absorber layers	Table 3	Table 3 focuses on lead iodide, lead bromide, and lead chloride, which are core metal halide sources for forming lead-based absorber layers	Tables 2 and 1	Select the lead halide according to the target bandgap, then combine it with A-site salts and the solvent system to define the first-round film-forming conditions
Study tin-based or mixed lead–tin low-bandgap perovskites	Table 3	Table 3 includes tin halides and tin fluoride, which can be used for tin-based systems, low-bandgap absorber layers, and studies on controlling tin oxidation	Tables 2 and 4	Tin-based systems require simultaneous attention to precursor purity, tin oxidation, defect passivation, and the crystallization process
Address thin-film surface defects, grain-boundary recombination, and interfacial stability issues	Table 4	Table 4 focuses on two-dimensional/quasi-two-dimensional interface modifiers, small-cation passivation salts, and crystallization modifiers	Tables 5 and 6	When the open-circuit voltage is low, hysteresis is obvious, or stability is insufficient, surface treatment and interface-modification strategies can first be screened from Table 4
Construct two-dimensional/three-dimensional interfaces or surface protective layers	Table 4	Materials such as phenethylammonium salts and butylammonium salts can be used for surface two-dimensionalization, grain-boundary passivation, and studies on moisture/oxygen tolerance	Tables 2 and 3	Suitable for improving surface recombination and interfacial stability after the formulation of the three-dimensional absorber layer has been determined
Select electron transport layers, hole transport layers, and interfacial buffer layers	Table 5	Table 5 covers electron-transport materials, hole-transport materials, interfacial layers, and doping additives, making it suitable for building complete device structures	Tables 1 and 4	After absorber-layer film formation has been determined, screening should consider transport-layer energy levels, wettability, interfacial reactions, and hysteresis behavior
Troubleshoot low open-circuit voltage, poor fill factor, or obvious hysteresis	Table 5	These problems are often related to transport-layer selection, interfacial recombination, charge extraction, and dopant systems	Table 4	If recombination losses remain after adjusting the transport layer, Table 4 should be consulted to examine surface defects and interfacial passivation
Establish representative perovskite material references or validate single-source precursor routes	Table 6	Table 6 lists representative preformed perovskite absorber materials and metal electrode materials, making it convenient for material comparison and device-structure validation	Tables 5 and 1	It can be used to compare methylammonium-, formamidinium-, and cesium-based absorber materials in terms of film formation, bandgap, and device stability
Compare the effects of silver and gold electrodes on device degradation	Table 6	Table 6 includes commonly used metal electrode materials, which can be used to study electrode contact, halide migration, and interfacial reactions	Tables 5 and 4	Electrode stability evaluation should also consider the transport layer, interfacial layer, and perovskite surface treatment
Study all-inorganic cesium lead halide perovskite systems	Table 6	Table 6 includes representative cesium lead iodide and cesium lead bromide materials, suitable for studies on all-inorganic absorber layers and thermal stability	Tables 2 and 3	If an all-inorganic system needs to be prepared from precursor routes, Tables 2 and 3 can be used to select cesium salts and lead halides
Establish a complete first-round screening route from solution preparation to device fabrication	Table 1	Table 1 determines the precursor solution and crystallization basis, which is the starting point for whether the first round of experiments can form a usable film	Tables 2, 3, and 5	Devices can be built stepwise in the order of “solvent system—A-site and halide composition—metal halides—transport layers—electrodes”
Analyze whether stability degradation originates from the absorber layer, interface, or electrode	Table 4	Table 4 corresponds to surface defects, two-dimensional interfaces, and grain-boundary passivation, making it an important entry point for stability diagnosis	Tables 5 and 6	If degradation is accompanied by interfacial recombination, hysteresis, or electrode reactions, transport-layer and electrode materials should be evaluated together

Table 1 | Precursor Solution Preparation, Film Formation, and Antisolvent Systems

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Main precursor solvent	68-12-2	D119450	N,N-Dimethylformamide (DMF)	Anhydrous, ≥99.8%	Commonly used for dissolving lead halides, methylammonium salts, and formamidinium salts; can be combined with dimethyl sulfoxide to regulate coordination intermediates and the film-forming process
Antisolvent and organic-layer solvent	108-90-7	C431386	Chlorobenzene	Anhydrous, ≥99.8%	Commonly used for antisolvent treatment during spin coating and for preparing some organic transport layers; helps control rapid nucleation and surface morphology of perovskite films
Coordinating precursor solvent	872-50-4	M119668	1-Methyl-2-pyrrolidinone (NMP)	Anhydrous, ≥99.5%	A high-boiling polar solvent that can be used for slow crystallization, coating-based film formation, and precursor solvent-system screening
Coordinating precursor solvent	67-68-5	D119415	Dimethyl sulfoxide (DMSO)	Spectroscopic grade, ≥99.9% (GC)	Can form coordination intermediates with lead halides and slow crystallization; commonly used to improve the uniformity and coverage of perovskite films
Antisolvent and organic-layer solvent	108-88-3	T399681	Toluene	Semiconductor grade, ≥99%	Can be used for antisolvent treatment in some perovskite film-forming processes or for preparing organic functional layers; suitable for comparing how antisolvent evaporation rate affects film morphology
Main precursor solvent	96-48-0	H1520798	γ-Butyrolactone	PrimorTrace™, electronic grade	Can be used in high-concentration precursor solutions and slow-crystallization systems; suitable for coating processes, solvent-ratio optimization, and crystallization-kinetics studies

Table 2 | Precursors for A-Site Cation and Halide Composition Control

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
A-site organic cation and bromide source	6876-37-5	M433320	Methylammonium bromide (MABr)	Anhydrous, ≥99%	Provides methylammonium and bromide components; can be used for methylammonium lead bromide systems, mixed iodide–bromide systems, and wide-bandgap perovskite composition control
A-site organic cation and bromide source	146958-06-7	F432132	Formamidinium bromide	Anhydrous, ≥99%	Provides formamidinium and bromide components; can be used for formamidinium lead bromide systems, mixed-cation systems, and wide-bandgap absorber-layer formulations for tandem cells
A-site inorganic cation and iodide source	7789-17-5	C1516026	Cesium iodide	PrimorTrace™, ≥99.99% metals basis, shot	Provides cesium and iodide components; can be used for mixed-cation perovskites, all-inorganic cesium lead iodide systems, and phase-stability control studies
A-site inorganic cation and bromide source	7787-69-1	C292202	Cesium bromide	PrimorTrace™, ultra-dry grade, ≥99.99% metals basis	Provides cesium and bromide components; can be used for cesium lead bromide systems, mixed-halide systems, and wide-bandgap perovskite material design
A-site organic cation and iodide source	14965-49-2	M492475	Methylammonium iodide (MAI)	PrimorTrace™, ≥99.99% metals basis	A classic methylammonium iodide source; can be used for methylammonium lead iodide absorber layers, mixed-cation systems, and reference device formulations
A-site organic cation and iodide source	879643-71-7	F492019	Formamidinium iodide (FAI)	≥99.5% (4 Times Purification)	A core precursor for formamidinium lead iodide systems; can be used for high-efficiency iodide-based perovskite absorber layers and mixed-cation phase-stability studies

Table 3 | B-Site Metal Halides, Tin-Based Components, and Lead–Tin System Precursors

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Lead-based B-site metal and iodide source	10101-63-0	L292078	Lead iodide	PrimorTrace™, ultra-dry grade, ≥99.999% metals basis	A core precursor for lead-based iodide absorber layers; can be used to prepare methylammonium lead iodide, formamidinium lead iodide, and mixed-cation perovskite films by one-step or two-step methods
Tin-based B-site metal and iodide source	10294-70-9	T292327	Tin iodide	PrimorTrace™, ultra-dry grade, ≥99.99% metals basis	A precursor for tin-based and mixed lead–tin perovskites; can be used for low-bandgap absorber layers, lead-free or low-lead systems, and studies on tin oxidation stability
Lead-based B-site metal and chloride source	7758-95-4	L407489	Lead chloride	PrimorTrace™, ultra-dry grade, ≥99.99% metals basis	Can be used in chloride-containing precursor systems and crystallization-control studies; helps compare the influence of chloride sources on grain growth, film uniformity, and interfacial properties
Lead-based B-site metal and bromide source	10031-22-8	L119346	Lead bromide	PrimorTrace™, ≥99.999% metals basis	A core precursor for lead bromide perovskites and mixed iodide–bromide perovskites; can be used for wide-bandgap absorber layers, tandem top-cell materials, and phase-separation studies
Tin-based stabilizing additive	7783-47-3	T195033	Tin(II) Fluoride	≥99%	Commonly used in tin-based perovskite systems to regulate tin vacancies and tin oxidation; helps reduce defects and leakage risks in tin-based absorber layers
Tin-based B-site metal and bromide source	10031-24-0	T302028	Tin(II) bromide	≥99%	Can be used for tin-based bromide or mixed lead–tin halide perovskite research; suitable for comparing how tin sources and bromide components affect bandgap, crystallization, and stability

Table 4 | Two-Dimensional/Quasi-Two-Dimensional Interface Modifiers, Defect Passivation, and Crystallization-Control Materials

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Small-cation defect-passivation salt	19227-70-4	G432266	Guanidinium iodide	Anhydrous, ≥99%	Can be used in mixed-cation systems, surface defect passivation, and lattice-environment regulation; suitable for studying the influence of small cations on film formation, recombination, and stability
Crystallization-control additive	1762-95-4	A112659	Ammonium thiocyanate	PrimorTrace™, ≥99.99% metals basis	Can be used to regulate the crystallization process, grain growth, and defect state of perovskite precursors; suitable for film-forming process and additive screening studies
Two-dimensional/quasi-two-dimensional interface modifier	53916-94-2	P290339	Phenethylammonium bromide	≥99.5% (4 times recrystallized)	A bulky organic ammonium bromide salt that can be used to construct surface two-dimensional perovskite layers, passivate interfacial defects, and regulate the surface properties of wide-bandgap perovskites
Two-dimensional/quasi-two-dimensional interface modifier	151059-43-7	P493125	Phenylethylammonium Iodide	≥99.5% (4 Times Purification)	Commonly used for two-dimensional/three-dimensional interface passivation and surface protection; can reduce surface recombination and improve the tolerance of perovskite films to moisture and oxygen
Two-dimensional/quasi-two-dimensional interface modifier	36945-08-1	B492157	Butylammonium Iodide (BAI)	≥99% (4 Times Purification)	A linear alkylammonium iodide salt that can be used for surface two-dimensionalization, grain-boundary passivation, and damp-heat stability studies; excessive dosage may increase charge-transport resistance

Table 5 | Electron Transport Layers, Hole Transport Layers, Interfacial Layers, and Doping Additives

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Electron-transport/hole-blocking interfacial material	4733-39-5	B293611	2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)	Sublimed grade, ≥99.8% metals basis	Commonly used as an interfacial buffer between fullerene layers and metal electrodes; improves electron collection and reduces reverse hole transport and interfacial recombination
Electron transport layer material	13463-67-7	N1519826	Nano Titanium oxide	Electronic grade, ≥99.8% metals basis, 300–700 nm	A classic electron transport material for n-i-p perovskite devices; suitable for studying electron extraction, interfacial treatment, and ultraviolet-light stability
Electron transport layer material	18282-10-5	S105111	Tin oxide	PrimorTrace™, ≥99.99% metals basis, 50–70 nm	A low-temperature electron transport layer material for n-i-p devices and flexible-substrate processes; commonly used to improve electron extraction and interfacial energy-level matching
Hole transport layer material	1313-99-1	N108312	Nickel oxide	PrimorTrace™, ≥99.99% metals basis	An inorganic hole transport material for p-i-n devices; suitable for improving thermal stability and studying the perovskite/hole-transport-layer interface
Hole transport layer material	155090-83-8	P191136	Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)	PEDOT:PSS = 1:6, 1.5% in water	Commonly used as a low-temperature hole transport layer in p-i-n structures; can be used to study interfacial wetting, film-formation compatibility, and device hysteresis
Hole transport layer material	1333317-99-9	P292965	Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]	Mw = 15000–25000	A hydrophobic polymeric hole transport material that can be used in high-efficiency p-i-n or n-i-p devices; suitable for studying interfacial energy levels, film uniformity, and stability
Hole transport layer dopant additive	90076-65-6	B398978	Bis(trifluoromethane)sulfonimide lithium salt (LiTFSI)	≥99.9%	Commonly used to dope organic hole transport layers and improve hole transport capability; in stability studies, moisture absorption, ion migration, and interfacial effects should be considered
Hole transport layer material	207739-72-8	S432310	Spiro-MeOTAD	≥99.9%	A classic organic hole transport material commonly used in n-i-p perovskite solar cells; can be combined with lithium salts and pyridine-type additives to regulate transport performance
Electron transport layer material	160848-22-6	P400139	[6,6]-Phenyl C 61 methyl butyrate	≥99.5%	A fullerene-derivative electron transport material commonly used in p-i-n devices; can improve electron extraction and passivate some surface defects of perovskites
Hole transport layer auxiliary additive	3978-81-2	T399526	4-tert-Butylpyridine	≥98%	Commonly used together with Spiro-MeOTAD systems to regulate the film formation and doping environment of the hole transport layer; its long-term influence on the perovskite interface should also be considered

Table 6 | Metal Electrodes, Representative Perovskite Materials, and Single-Source Precursors

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Metal electrode material	7440-22-4	S434801	Silver	PrimorTrace™, ≥99.99% metals basis, powder, <250 μm	A commonly used metal-electrode-related material; can be used for studying silver-electrode stability, metal diffusion, and halide reactions; specific preparation should match evaporation, sputtering, printing, or paste-based processes
Metal electrode material	7440-57-5	G434760	Gold	≥99.99% metals basis, powder, <850 μm, ≥99.99% trace metals basis	A commonly used metal-electrode-related material; can be used as a gold-electrode material reference and for studying contact stability, metal diffusion, and interfacial reactions; specific electrode preparation should match evaporation, sputtering, printing, or paste-based processes and confirm compatibility between material form and process
Representative iodide-based perovskite absorber material	69507-98-8	P304421	Methylammonium lead iodide	≥99%	A classic iodide-based perovskite absorber material; can be used for reference devices, structure–property relationship studies, and thin-film stability comparisons
Representative bromide-based perovskite absorber material	1008105-17-6	F493690	Formamidinium Lead Bromide	≥99%	A formamidinium lead bromide perovskite material; can be used for wide-bandgap absorber layers, bromide-based perovskite film formation, and mixed-halide system comparisons
Representative iodide-based perovskite absorber material	1451592-07-6	F493684	Formamidinium Lead Iodide	≥99%	A formamidinium lead iodide perovskite material; can be used for high-efficiency iodide-based absorber layers, phase stability studies, and mixed-cation system research
Representative bromide-based perovskite absorber material	69276-13-7	P491784	Methylammonium tribromoplumbate	≥99%	A methylammonium lead bromide perovskite material; can be used for wide-bandgap absorber layers, bromide-based perovskite devices, and bandgap-control references
Representative all-inorganic bromide-based perovskite absorber material	15243-48-8	C302972	Cesium Lead Tribromide	≥98%	An all-inorganic cesium lead bromide perovskite material; can be used for wide-bandgap devices, all-inorganic systems, and thermal-stability studies
Representative all-inorganic iodide-based perovskite absorber material	18041-25-3	C305228	Cesium Lead Triiodide	≥98%	An all-inorganic cesium lead iodide perovskite material; can be used for all-inorganic absorber layers, black-phase stabilization, and device thermal-stability studies

Note: The above are representative Aladdin products. For more product specifications, search by “product name/CAS/catalog number” on the Aladdin official website.

References

[1] Kojima A., Teshima K., Shirai Y., Miyasaka T. Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells. Journal of the American Chemical Society, 2009, 131: 6050–6051.

[2] U.S. Department of Energy. Perovskite Solar Cells.

[3] U.S. Department of Energy. Perovskite Research Directions.

[4] Khenkin M. V., Katz E. A., Abate A., et al. Consensus statement for stability assessment and reporting for perovskite photovoltaics based on ISOS procedures. Nature Energy, 2020, 5: 35–49.

[5] Boyd C. C., Cheacharoen R., Leijtens T., McGehee M. D. Understanding Degradation Mechanisms and Improving Stability of Perovskite Photovoltaics. Chemical Reviews, 2019, 119: 3418–3451.

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