Two-Dimensional CH3NH3PbI3 with High Efficiency and Superior Carrier Mobility: A Theoretical Study

Two-dimensional (2D) halide perovskites have distinct tunable compositional and structural properties, which make 2D materials a good candidate to improve the characteristics of photovoltaic applications. We have explored strain-dependent structural, electronic, and optical properties of organic inorganic hybrid perovskite CH3NH3PbI3 monolayers using density functional calculations. Here, we have calculated carrier mobility of electrons and holes and the band gap of the CH3NH3PbI3 monolayer. The results suggest that with increasing tensile and compressive strains, the band gap increases up to 5% (in the case of tensile strain), whereas decreases toward instability, i.e., 9% (in the case of compressive strain). The carrier mobility of 2D CH3NH3PbI3 is approximately 16 times larger than that of the bulk form of CH3NH3PbI3. Furthermore, we have also investigated optical properties, which show good activity in the visible as well as in the high-ultraviolet region of the spectrum. In addition, the 2D CH3NH3PbI3 monolayer shows good transmittance (>80%) in a lower energy range as well as high absorption coefficient of 14.09 X 10(5) cm(-1) at 8.8 eV, which is up to 40% higher than that of the bulk form of CH3NH3PbI3; however, under both types of strains, the absorption coefficient is decreased in the 2D CH3NH3PbI3 monolayer. For photovoltaic applications, we have calculated the open-circuit voltage (V-oc), fill factor (FF), short-circuit current density (J(sc)), and power conversion efficiency (eta) of the 2D CH3NH3PbI3 monolayer. Our theoretical results suggest that the power conversion efficiency (eta) is 28%, which is higher than that of its bulk form and 5% less than the Shockley-Queisser limit (33%), suggesting that 2D CH3NH3PbI3 is a good candidate for the solar cell application.