Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency

Abstract

Today's best perovskite solar cells use a mixture of formamidinium and methylammonium as the monovalent cations. Adding cesium improves the compositions greatly.

Ambipolar Triple Cation Perovskite Field Effect Transistors and Inverters

“…Such good stability is not surprising since triple cation perovskite is known to exhibit environmentally stable photovoltaic performance. [13] In our previous study, we demonstrate that perovskite thin films slowly degrade (at 130 °C for 3 h) when loaded with 10% Cs cation, whereas the perovskite thin films experience severe degradation after heat treatment, by an observable decrease in absorption coefficient. Hence, we believe that with appropriate amount of Cs cation could stabilize the perovskite structure.…”

“…[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).…”

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

“…Recently, two separate works have demonstrated that adding Cs to the FAPbI 3 can also structurally stabilize the FA-based perovskite and specifically enhance its stability toward this black-to-yellow phase transition in humid air. [56,57] Recently we have introduced a new perovskite composition comprising FA 0.83 Cs 0.17 Pb(I 0.6 Br 0.4 ) 3 , which we have already shown to work very well as a wider band gap perovskite absorber, and exhibit improved stability to halide segregation and thermal stability, as compared with MAPb(I 0.6 Br 0.4 ) 3 . [55] However, as of yet we have not proven this new material to have superior long-term operational stability.…”

Alkali Metal Doping for Improved CH3NH3PbI3 Perovskite Solar Cells

“…have attracted great attention owing to their superior photoelectronic properties 1, 2, 3, 4, 5. As a type of star material in the photovoltaic field, the performance of perovskite‐based thin film solar cells have gone through tremendous advance, almost caught up with or even gone beyond the efficiency of crystalline silicon, CIGSe (copper–indium–gallium diselenide) and CdTe solar cells only in a few years 1, 6, 7, 8, 9, 10. And the high efficiency perovskite solar cell depends on the high‐quality absorbing layer governed by its deposition process including nucleation and thin film growth.…”