Intrinsic Thermal Instability of Methylammonium Lead Trihalide Perovskite

Abstract

Organolead halide perovskites currently are the new front‐runners as light absorbers in hybrid solar cells, as they combine efficiencies passing already 20% with deposition temperatures below 100 °C and cheap solution‐based fabrication routes. Long‐term stability remains a major obstacle for application on an industrial scale. Here, it is demonstrated that significant decomposition effects already occur during annealing of a methylammonium lead triiode perovskite at 85 °C even in inert atmosphere thus violating international standards. The observed behavior supports the view of currently used perovskite materials as soft matter systems with low formation energies, thus representing a major bottleneck for their application, especially in countries with high average temperatures. This result can trigger a broader search for new perovskite families with improved thermal stability.

A stable lead halide perovskite nanocrystals protected by PMMA

“…S7a), while the PLAR sample maintained bright green emission even after 90 days (Fig. S7b), which shows the best stability compared with the previous results [20].…”

“…The other method to stabilize HOIPs against water is covering them with waterresistant materials including mesoporous inorganic matrices [19][20][21][22] or organic small molecules [23]. Most recently, microencapsulation of polymer was found to offer a barrier to moisture [24][25][26][27], but the methods tend to generate lead ions at the surface and the easily exfoliated coating due to the weak chemical bonds [28].…”

Efficient and Air‐Stable Mixed‐Cation Lead Mixed‐Halide Perovskite Solar Cells with n‐Doped Organic Electron Extraction Layers

“…[50] A fundamental issue with the MAPbI 3 based perovskite is the relative volatility of methylammonium iodide (MAI), which evolves out of the film during heating, and this process is accelerated in an atmosphere containing moisture. [5,[51][52][53] In addition, the MAPbI 3 has also been shown to degrade more rapidly when exposed to light in an atmosphere containing oxygen, due to a chemical reaction between oxygen and MA + in the presence of electronic charge in the perovskite. [54] We have previously shown that formamidinium (FA)-based perovskites are much more thermally stable than methylammonium (MA)-based perovskite.…”

Ambipolar Triple Cation Perovskite Field Effect Transistors and Inverters

“…[4] Formamidinium lead iodide (FAPbI 3 ) is an interesting material due to its enhanced absorption in the red than that of MAPbI 3 ; however, the structural stability of α-phase is not good and slowly converts into a yellow hexagonal δ-phase. The inorganic perovskite, CsPbX 3 , where Cs cation is less volatile, therefore is suitable to improve thermal stability [4][5][6][7][8][9][10][11][12][13] but it is also to circumvent the δ-phase impurities, which acts as recombination centers hampering further progress. There has been a growing interest in MAPbI 3 perovskite for use in light-emitting field effect transistors, [14] hybrid perovskite phototransistor, [15] and hybrid halide perovskite field effect transistors (PFETs).…”

“…Although having optimal bandgap, high absorption coefficient, and long-range exciton diffusion length, [1][2][3] methylammonium lead iodide (MAPbI 3 ) deteriorates at 85 °C due to the volatility of MA (methylammonium) cation. [4] Formamidinium lead iodide (FAPbI 3 ) is an interesting material due to its enhanced absorption in the red than that of MAPbI 3 ; however, the structural stability of α-phase is not good and slowly converts into a yellow hexagonal δ-phase. The inorganic perovskite, CsPbX 3 , where Cs cation is less volatile, therefore is suitable to improve thermal stability [4][5][6][7][8][9][10][11][12][13] but it is also to circumvent the δ-phase impurities, which acts as recombination centers hampering further progress.…”