Methylammonium Lead Triiodide Research Articles

HPMC-Mediated ZnCl2 Doping Possible Substitution of Pb2+ for Environment-Friendly Halide Perovskite Solar Cell Fabrication

Research on halide perovskite solar cells is a rapidly evolving and active area of study within the field of photovoltaics. Replacement of lead from halide perovskite solar cells is a prerequisite due to its toxicity. In this research, an efficient and low surface defect of Zn2+ incorporated hybrid perovskite material was demonstrated, where Pb2+ is partially substituted with transitional metal Zinc. Herein, we report the incorporation of dopant material ZnCl2 with synthetic cellulose HPMC (Hydroxy propyl methyl cellulose) as a dopant to improve the surface morphology, crystallinity, and partial substitution of Pb2+ with Zn2+. Samples were prepared with different composition of ZnCl2 doping assisted with HPMC in MAPbI3 (methylammonium lead triiodide) for perovskite layer preparation. A device assembly of layer-by-layer architecture constituting FTO/TiO2(ETL)/MAPbI3/CuSCN(HTL) was fabricated for the experimental analysis. The as-prepared perovskite samples were characterized using different analytical tools to investigate optical absorption property, crystalline structure, functional group interaction, and surface morphology, respectively. Finally, the electrical performance of the perovskite solar cells was tested under AM 1.5 G solar illumination, and the data affirms that 10 wt% ZnCl2 doping assisted with HPMC media exhibits optimum performance with improved film quality.

Methylammonium lead triiodide perovskite-based solar cells efficiency: Insight from experimental and simulation

This work deals with the growth investigation of the methylammonium lead triiodide (MAPbI3) thin films prepared by the spin coating technique.Firstly, MAPbI3 films were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and UV–Visible spectroscopy as well as photoluminescence techniques are used to calculate the band gap energy. Indeed, the high-quality MAPbI3 perovskite films were obtained by using Chlorobenzene as an antisolvent with good crystallinity, large grain sizes, and higher absorption compared to MAPbI3 treated by toluene. Secondly, the performance of FTO/TiO2/MAPbI3/Spiro OMeTAD/Au perovskite solar cell was evaluated using a numerical simulation of the Solar Cell by SCAPS simulator. The effect of the structural and physical parameters of MAPbI3 absorber layer and HTL with the different antisolvents, including thickness, defect density, total charge density, donor density and electron affinity. Obtained results are: Jsc of 25.96 mA/cm2, PCE of 30.70%, Voc of 1.259 V, FF of 88.93% of MAPbI3-based solar cells when MAPbI3 is treated by toluene. However, for MAPbI3- Chlorobenzene, the I–V characteristics are rather: Jsc of 28.18 mA/cm2, PCE of 31.81%, FF of 88.19% and Voc of 1.200 V. It is pointed out that the use of chlorobenzene may be of interest to improve the perovskites solar cells performances.

Spin–Orbit Coupling Notably Retards Non-radiative Electron–Hole Recombination in Methylammonium Lead Triiodide Perovskites

The giant spin-orbit coupling (SOC) of a heavy lead element significantly extends charge carrier lifetimes of lead halide perovskites (LHPs). The physical mechanism remains unclear and requires a quantum dynamics perspective. Taking methylammonium lead iodide (MAPbI3) as a prototypical system and using non-adiabatic molecular dynamics combined with 1/2 electron correction, we show that SOC notably reduces the non-radiative electron-hole (e-h) recombination by decreasing the non-adiabatic coupling (NAC) primarily as a result of SOC decreasing the e-h wave function overlap by reshaping the electron and hole wave functions. Second, SOC causes spin mismatch subject to spin-mixed states, which further decreases NAC. The charge carrier lifetime is about 3-fold longer in the present of SOC relative to the absence of SOC. Our study generates the fundamental understanding of SOC minimizing non-radiative charge and energy losses in LHPs.

Electronic Structure and Chemical Bonding in Methylammonium Lead Triiodide and Its Precursor Methylammonium Iodide.

A detailed examination of the electronic structures of methylammonium lead triiodide (MAPI) and methylammonium iodide (MAI) is performed with ab initio molecular dynamics (AIMD) simulations based on density functional theory, and the theoretical results are compared to experimental probes. The occupied valence bands of a MAPI single crystal and MAI powder are probed with X-ray photoelectron spectroscopy, and the conduction bands are probed from the perspective of nitrogen K-edge X-ray absorption spectroscopy. Combined, the theoretical simulations and the two experimental techniques allow for a dissection of the electronic structure unveiling the nature of chemical bonding in MAPI and MAI. Here, we show that the difference in band gap between MAPI and MAI is caused chiefly by interactions between iodine and lead but also weaker interactions with the MA+ counterions. Spatial decomposition of the iodine p levels allows for analysis of Pb-I σ bonds and π interactions, which contribute to this effect with the involvement of the Pb 6p levels. Differences in hydrogen bonding between the two materials, seen in the AIMD simulations, are reflected in nitrogen valence orbital composition and in nitrogen K-edge X-ray absorption spectra.

The Effect of Short Chain Carboxylic Acids as Additives on the Crystallization of Methylammonium Lead Triiodide (MAPI)

Due to their exceptional properties, the study of hybrid perovskite (HyP) structures and applications dominate current photovoltaic prospects. Methylammonium lead tri-iodide perovskite (MAPI) is the model compound of the HyP class of materials that, in a few years, achieved, in photovoltaics, a power conversion efficiency of 25%. The attention on HyP has recently moved to large single crystals as emerging candidates for photovoltaic application because of their improved stability and optoelectronic properties compared to polycrystalline films. To control the quality and symmetry of the large MAPI single crystals, we proposed an original method that consisted of adding short-chain carboxylic acids to the inverse temperature crystallization (ICT) of MAPI in γ-butyrolactone (GBL). The crystals were characterized by single-crystal X-ray diffraction (SC-XRD), X-ray powder diffraction (XRPD) and Raman spectroscopy. Based on SC-XRD analysis, MAPI crystals grown using acetic and trifluoroacetic acids adopt a tetragonal symmetry “I4cm”. MAPI grown in the presence of formic acid turned out to crystallize in the orthorhombic “Fmmm” space group demonstrating the acid’s effect on the crystallization of MAPI.

Core-twisted tetrachloroperylenediimide additives improve the crystallinity of perovskites to provide efficient perovskite solar cells

Defects at the grain boundaries and surfaces of metal-halide perovskite films function as non-radiative recombination centers that decrease the performance and/or stability of perovskite solar cells (PSCs). The incorporation of additives into perovskite films can improve their quality and, thereby, provide high-performance PSCs. In this study, we introduced core-twisted tetrachloroperylene diimide (ClPDI) derivatives (n-type small molecules) into the lead iodide precursor solution and used a two-step deposition method to prepare methylammonium lead triiodide (MAPbI3) perovskite films. We examined the effects of the terminal functional groups of the ClPDI derivatives—n-butyl (ClPDI-C4), dimethylaminopropyl (ClPDI-C3DMeA), and aminopropyl (ClPDI-DPA) — on their ability to control the crystallization rate and modulate the film morphology. The power conversion efficiency of the PSC prepared without an additive (15.88%) improved to 16.88 and 18.77% after incorporation of ClPDI-C4 and ClPDI-DPA, respectively, because the strong interactions between these additives and the perovskite passivated defects, slowed the rate of perovskite crystal growth, and increased the grain size. Thus, the use of ClPDI additives in perovskite films can effectively enhance both the efficiency and stability of PSCs.

Stable Pure Iodide MA0.95Cs0.05PbI3 Perovskite toward Efficient 1.6 eV Bandgap Photovoltaics.

Perovskite photovoltaics with the advantages of facile fabrication and high efficiency have been the rising star in the field for a decade. Methylammonium lead triiodide (MAPbI3) was the first widely studied perovskite to initiate the boom of perovskite photovoltaics, but it was later considered thermodynamically instable for commercialization. Here, we demonstrate that simple cesium (Cs) doping without any complicated process can form a stable MA-based perovskite with a widened bandgap, which may broaden the application of MA-based perovskites in tandem solar cells. A record-high efficiency of ≤22% is thus achieved for a 1.6 eV bandgap perovskite solar cell. This work not only provides a new stable and efficient pure iodide candidate as a 1.6 eV bandgap perovskite but also reveals that Cs incorporation can help improve the efficiency and stability of MA-based perovskites.

Influence of layer thickness, defect density, doping concentration, interface defects, work function, working temperature and reflecting coating on lead-free perovskite solar cell

Perovskite-based solar cells have made an impact in the photovoltaic industry by surpassing some of the established solar cell technologies, with power conversion efficiency (PCE) exceeding 23% already. Among them methylammonium lead tri iodide (MAPbI3) based perovskite solar cell (PSC) have been greatly focused upon. However, the toxic nature of lead (Pb) is a major area of concern in its wide spread applications. Nontoxic germanium (Ge) has emerged as an alternate to Pb in PSC due to its similar photovoltaic properties. In this work, numerical modelling of Ge based perovskite solar cell structure (FTO/TiO2/CH3NH3GeI3/Spiro-OMeTAD/Au) is performed using SCAPS software. A systematic approach is followed to investigate the effect of material thickness, doping concentration, work function, temperature, reflection and interface defect densities on the performance of PSC. Initially, all the cell parameters are optimized by keeping defect density constant. Once, the optimized structure is achieved the defect density is varied to investigate its effect on the cell performance. Finally, all the cell parameters are optimized at each defect density. Based on optimized simulation results, PCE of 17.74% is achieved with 15.77 mA/cm2 short-circuit current (JSC), 1.26 V open circuit voltage (VOC) and 88.64% fill factor (FF). Moreover, in the optimized cell structure Spiro-OMeTAD and gold (Au) are replaced with different copper (Cu) based hole transport layer (HTL) and anode materials respectively to study its effect on the cell performance. The best result is obtained with copper antimony sulfide (CuSbS2) and Copper Aluminate (CuAIO2) exhibiting PCE of 21.42% and 23.56% respectively.

Impedance spectroscopy study of defect/ion mediated electric field and its effect on the photovoltaic performance of perovskite solar cells based on different active layers

Effect of defects mitigation on the photovoltaic (PV) performance of three different types of perovskite solar cells (PSCs), namely, single halide (methylammonium lead triiodide, MAPbI 3 ), mixed halide (MAPbI x Cl 3-x ) and phenyl-C71-butyric acid methyl ester (PC 71 BM) based bulk heterojunction (MAPbI 3 -PC 71 BM) PSCs is studied using impedance and transient spectroscopy as a function of dc voltage bias. Parameters extracted from impedance spectra and transient signals are quantitatively analysed to understand the operation mechanism of each PSC. Among the PSCs, the low frequency capacitance (C lf ) values obtained near to the open circuit voltage (V OC ), where charge carriers are restricted inside the device, are found to be minimum for MAPbI 3 based PSCs. Whereas, bulk capacitance (C hf ), high frequency resistance (R hf ) and low frequency resistance (R lf ) values are obtained to be highest for the MAPbI 3 based device which exhibited the best power conversion efficiency (PCE) of 16%. The extracted impedance parameters suggest lessened defect or ion accumulation, improved charge storage capacity/charge life-time, reduced recombination losses and ion transport for the MAPbI 3 device, favoring performance enhancement. The characteristic time constants for the high frequency and low frequency processes also specify longer charge carrier lifetime and faster interfacial charge transfer process near to V OC in MAPbI 3 based PSCs. In addition, transient photocurrent and photovoltage analysis confirms the existence and interplay of ion induced electric field, built-in and applied external field. C lf , C hf , R lf and R hf values as well as transient responses are observed to be greatly dependent on the chemical composition, grain size, grain boundaries and pinholes formed in the perovskite active layer. Based on the results from impedance measurements and transient spectroscopy, the working mechanism of each PSC is proposed in view of the interplay among ion induced electric field, built-in-field and applied electric field. • Operation of three different perovskite solar cells during J-V characterisation. • Defects/ions ion movement and its consequence on the photovoltaic parameters. • The electric field imbalance due to ionic movement in perovskite solar cells.

Temperature-Dependent EXAFS Measurements of the Pb L3-Edge Allow Quantification of the Anharmonicity of the Lead–Halide Bond of Chlorine-Substituted Methylammonium (MA) Lead Triiodide

This article reports on studies of chlorine-substituted MAPbI3 using combined temperature-dependent XRD synchrotron and Pb-L3 edge EXAFS to analyze the anharmonicity of the lead halide bond. The EXAFS parameters were described in the orthorhombic phase by an Einstein or T2 type behavior, which was then compared with the experimental EXAFS parameters of the tetragonal/cubic phase. In the orthorhombic phase, it was observed that the asymmetry of the pair distribution function (cumulant C3) in MAPbCl3 is much lower than in MAPbI3. Compared with the behavior in the orthorhombic phase, the anharmonicity changed after the phase transition to the room temperature phase, with MAPbCl3 showing an increased anharmonicity and MAPbI3 a decrease. The differences between MAPbI3 and 2% chlorine substitution were small, both in the orthorhombic and tetragonal phases. By determining the structural parameters required to convert the effective force constants k0 and k3 resulting from the EXAFS analysis into the Morse potential parameters {\alpha} and D, we could establish that our results agree with other experimental findings. Moreover, by using XRD we found that the [PbX6] octahedra shrink slightly in the tetragonal phase of MAPbI3 and MAPbI2.94Cl0.06, towards increasing temperatures. This behavior in the tetragonal phase is related to the dominant negative tension effects observed by EXAFS.

SnO2/ZnO as double electron transport layer for halide perovskite solar cells

The energy loss in perovskite solar cells (PSCs) is a key factor that limits the potential scope of photovoltaic performance. Herein, we introduce a double electron transport layer (DETL) that consists of SnO2/ZnO and use it to prepare methylammonium lead triiodide (MAPbI3)-based planar heterojunction PSCs for mitigating the energy loss. We investigated the photovoltaic properties of DETL PSCs concerning the varying thickness of the ZnO layer. The thickness of DETL in each device was measured using an electron probe microanalyzer. UV–vis-NIR spectroscopic as well as different microscopic techniques including SEM and AFM were employed for an in-depth investigation of the prepared devices. The best PSC device in our study showed a comparatively improved energy conversion efficiency (ECE) of 15.22% with an optimized thickness of ZnO up to 210 nm.

Mechanism and Timescales of Reversible p-Doping of Methylammonium Lead Triiodide by Oxygen.

Understanding and controlling the energy level alignment at interfaces with metal halide perovskites (MHPs) is essential for realizing the full potential of these materials for use in optoelectronic devices. To date, however, the basic electronic properties of MHPs are still under debate. Particularly, reported Fermi level positions in the energy gap vary from indicating strong n- to strong p-type character for nominally identical materials, raising serious questions about intrinsic and extrinsic defects as dopants. ​In this work, photoemission experiments demonstrate that thin films of the prototypical methylammonium lead triiodide (MAPbI3 ) behave like an intrinsic semiconductor in the absence of oxygen. Oxygen is then shown to be able to reversibly diffuse into and out of the MAPbI3 bulk, requiring rather long saturation timescales of ≈1 h (in: ambient air) and over 10 h (out: ultrahigh vacuum), for few 100nm thick films. Oxygen in the bulk leads to pronounced p-doping, positioning the Fermi level universally ≈0.55eV above the valence band maximum. The key doping mechanism is suggested to be molecular oxygen substitution of iodine vacancies, supported by density functional theory calculations. This insight rationalizes previous and future electronic property studies of MHPs and calls for meticulous oxygen exposure protocols.

THE STABILITY STUDIES OF MIXED HALIDE PEROVSKITE CH3NH3PbBrXI3-X THIN FILMS IN AMBIENT WITH AIR HUMIDITY 70% USING UV-VIS SPECTROSCOPY AND X-RAY DIFFRACTION

Perovskite Solar Cells (PSC), with the efficiency of more than 22%, has shown promising prospects for the future of environmentally friendly technology. However, low stability on humidity is a major problem limiting the commercialization of PSC. The perovskite material commonly used as a perovskite solar-cell active material is methylammonium lead tri-iodide (CH3NH3PbI3 or MAPbI3) prepared with a mixture of methylammonium-iodide (MAI) and lead iodide (PbI2). Perovskite material MAPbI3 is hygroscopic and easily decomposed into its constituent material, thereby reducing the performance of the PSC. Meanwhile, perovskite methylammonium lead-bromide (MAPbBr3) has higher moisture stability than MAPbI3 because it has a cubic crystal structure that has high symmetry. However, the efficiency of solar cells using MAPbBr3 as active material is lower than that of MAPbI3, due to a higher bandgap (~2.2 eV) than that of MAPbI3 (~1.5 eV). Therefore the wavelength range of sunlight absorbed by MAPbBr3 is shorter. We have studied the effect of the ratio of Bromium ion (Br-) insertion into MAPbI3 perovskite, forming mixed perovskite halide MAPbBrxI3-x on the stability of thin perovskite films in ambient with air humidity 70%. The value of x is varied from x = 0, 0.25, 0.5, 0.75 and 3. We measured the evolution of UV-Vis spectra and XRD patterns of thin perovskite films. The MAPbBr3 perovskite film is the most stable in high air relative humidity (> 70%). While mixed perovskite films with x = 0.5 are more stable as compared to the other x values based on absorption spectra. The XRD results showed that the stability of mixed halide perovskite is decreased with the increasing of x value.

Test of the Dynamic-Domain and Critical Scattering Hypotheses in Cubic Methylammonium Lead Triiodide

We investigate the hypothesis of dynamic tetragonal domains occuring in cubic CH$_3$NH$_3$PbI$_3$ using high-resolution neutron spectroscopy to study a fully deuterated single crystal. The $\textit{R}$-point scattering above the 327.5 K tetragonal-cubic phase transition is always resolution-limited in energy and therefore inconsistent with dynamic domain predictions. This behavior is instead consistent with the central peak phenomenon observed in other perovskites. The scattering may originate from small, static, tetragonal-phase domains nucleating about crystal defects, and the temperature dependence demonstrates the transition is first-order.

First-Principles Investigation of the Thermal Degradation Mechanisms of Methylammonium Lead Triiodide Perovskite

The poor stability of organometallic halide perovskites, especially CH3NH3PbI3 (MAPbI3), in high-temperature environments is one of the challenges retarding its wider applicability. A better understanding of how MAPbI3 perovskite degrades thermally will allow us to develop strategies to improve its “intrinsic” stability. In this study, we employed first-principles density functional theory to obtain detailed thermal degradation energy landscapes for MAPbI3. We focused on studying two reaction pathways: P1, for proton abstraction from methylammonium (MA) to iodine, and P2, for substitution (SN2) of an iodide anion (I–, as nucleophile) at the carbon atom of MA to yield iodomethane (CH3I) and ammonia (NH3). Our calculations provided kinetic data, allowing us to assess the “intrinsic” (in)stability of MAPbI3 under heat stress and to make sense of the seemingly contradictory experimental results. The I– species is more reactive for reaction P1 but not for P2. The energy of the reaction along pathway P1 increases monotonically with respect to proton abstraction. The reaction along pathway P2 is a two-step process, with a CH3–I–Pb–X intermediate formed in the crystal in conjunction with the release of NH3 gas. Our results suggest that the method of preparation (e.g., iodine-deficient conditions) and the morphology (e.g., improved crystallinity) of MAPbI3 could both influence its thermal stability.

Blading Phase-Pure Formamidinium-Alloyed Perovskites for High-Efficiency Solar Cells with Low Photovoltage Deficit and Improved Stability.

Currently, blade-coated perovskite solar cells (PSCs) with high power conversion efficiencies (PCEs), that is, greater than 20%, normally employ methylammonium lead tri-iodide with a sub-optimal bandgap. Alloyed perovskites with formamidinium (FA) cation have narrower bandgap and thus enhance device photocurrent. However, FA-alloyed perovskites show low phase stability and high moisture sensitivity. Here, it is reported that incorporating 0.83 molar percent organic halide salts (OHs) into perovskite inks enables phase-pure, highly crystalline FA-alloyed perovskites with extraordinary optoelectronic properties. The OH molecules modulate the crystal growth, enhance the phase stability, passivate ionic defects at the surface and/or grain boundaries, and enhance the moisture stability of the perovskite film. A high efficiency of 22.0% under 1 sun illumination for blade-coated PSCs is demonstrated with an open-circuit voltage of 1.18 V, corresponding to a very small voltage deficit of 0.33 V, and significantly improved operational stability with 96% of the initial efficiency retained under one sun illumination for 500 h.

Direct Silicon Heterostructures With Methylammonium Lead Iodide Perovskite for Photovoltaic Applications

We investigated the formation of photovoltaic (PV) devices using direct n-Si/MAPI (methylammonium lead tri-iodide) two-sided heterojunctions for the first time (as a possible alternative to two-terminal tandem devices) in which charge might be generated and collected from both the Si and MAPI. Test structures were used to establish that the n-Si/MAPI junction was photoactive and that spiro-OMeTAD acted as a “pinhole blocking” layer in n-Si/MAPI devices. Two-terminal “substrate” geometry devices comprising Al/n-Si/MAPI/spiro-OMeTAD/Au were fabricated and the effects of changing the thickness of the semitransparent gold electrode and the silicon resistivity were investigated. External quantum efficiency and capacitance-voltage measurements determined that the junction was one-sided in the silicon-and that the majority of the photocurrent was generated in the silicon, with there being a sharp cutoff in photoresponse above the MAPI bandgap. Construction of band diagrams indicated the presence of an upward valence band spike of up to 0.5 eV at the n-Si/MAPI interface that could impede carrier flow. Evidence for hole accumulation at this feature was seen in both Kelvin-probe transients and from unusual features in both current-voltage and capacitance-voltage measurements. The devices achieved a hysteresis-free best power conversion efficiency of 2.08%, VOC 0.46 V, JSC 11.77 mA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and FF 38.4%, demonstrating for the first time that it is possible to create a heterojunction PV device directly between the MAPI and n-Si. Further prospects for two-sided n-Si/MAPI heterojunctions are also discussed.

Position-locking of volatile reaction products by atmosphere and capping layers slows down photodecomposition of methylammonium lead triiodide perovskite.

The remarkable progress of metal halide perovskites in photovoltaics has led to the power conversion efficiency approaching 26%. However, practical applications of perovskite-based solar cells are challenged by the stability issues, of which the most critical one is photo-induced degradation. Bare CH3NH3PbI3 perovskite films are known to decompose rapidly, with methylammonium and iodine as volatile species and residual solid PbI2 and metallic Pb, under vacuum under white light illumination, on the timescale of minutes. We find, in agreement with previous work, that the degradation is non-uniform and proceeds predominantly from the surface, and that illumination under N2 and ambient air (relative humidity 20%) does not induce substantial degradation even after several hours. Yet, in all cases the release of iodine from the perovskite surface is directly identified by X-ray photoelectron spectroscopy. This goes in hand with a loss of organic cations and the formation of metallic Pb. When CH3NH3PbI3 films are covered with a few nm thick organic capping layer, either charge selective or non-selective, the rapid photodecomposition process under ultrahigh vacuum is reduced by more than one order of magnitude, and becomes similar in timescale to that under N2 or air. We conclude that the light-induced decomposition reaction of CH3NH3PbI3, leading to volatile methylammonium and iodine, is largely reversible as long as these products are restrained from leaving the surface. This is readily achieved by ambient atmospheric pressure, as well as a thin organic capping layer even under ultrahigh vacuum. In addition to explaining the impact of gas pressure on the stability of this perovskite, our results indicate that covalently “locking” the position of perovskite components at the surface or an interface should enhance the overall photostability.

Optical Properties of Perovskite Thin Film

Methyl-ammonium lead tri iodide (CH3NH3PbI3) perovskite thin films have been prepared by solution processing. Thin film after deposited in the laboratory ambient conditions by drop casting, it prepared by two step method PbI2 and CH3NH3I at the glass substrate. The analysis provides: the absorption coefficient, extinction coefficient, refractive indices, real and imaginary components of the dielectric constant of the CH3 NH3 PbI3 films, energy gap. Energy gap of perovskite thin films is reached 1.8 that is very important for solar cell application.

Facile and Controllable Fabrication of High‐Performance Methylammonium Lead Triiodide Films Using Lead Acetate Precursor for Low‐Threshold Amplified Spontaneous Emission and Distributed‐Feedback Lasers

Organic–inorganic lead halide perovskites have emerged rapidly as the most attractive materials for photovoltaics in the last 10 years. Intense research has been done on crystal growth and morphology control to improve their power conversion efficiencies. Furthermore, perovskites also show great potential for optical amplification and lasing. Despite the numerous reports on how processing conditions affect the perovskite light‐harvesting properties, effects on amplified spontaneous emission (ASE) or lasing performance have attracted considerably less attention. Herein, a detailed study on the ASE performance of methylammonium lead triiodide (MAPbI3) films, processed with lead acetate (Pb(Ac)2) as lead source following a one‐step spin‐coating method and exposed to different post‐deposition conditions, is presented. It is found that the use of Pb(Ac)2 instead of lead iodide (PbI2) accelerates the crystal growth and simplifies the fabrication procedure. Even very thin MAPbI3 films (≈70 nm) can sufficiently support optical amplification and lasing in surface‐emitting distributed‐feedback (DFB) cavities. The facile and highly controllable MAPbI3 film formation observed with Pb(Ac)2 as precursor makes it a preferred choice with respect to PbI2 for future perovskite laser diodes.