title: Investigation into the Advantages of Pure Perovskite Film without PbI2for High Performance Solar Cell.
abstract: In CH3NH3PbI3-based high efficiency perovskite solar cells (PSCs), tiny amount of PbI2impurity was often found with the perovskite crystal. However, for two-step solution process-based perovskite films, most of findings have been based on the films having different morphologies between with and without PbI2. This was mainly due to the inferior morphology of pure perovskite film without PbI2, inevitably produced when the remaining PbI2forced to be converted to perovskite, so advantages of pure perovskite photoactive layer without PbI2impurity have been overlooked. In this work, we designed a printing-based two-step process, which could not only generate pure perovskite crystal without PbI2, but also provide uniform and full surface coverage perovskite film, of which nanoscale morphology was comparable to that prepared by conventional two-step solution process having residual PbI2. Our results showed that, in two-step solution process-based PSC, pure perovskite had better photon absorption and longer carrier lifetime, leading to superior photocurrent generation with higher power conversion efficiency. Furthermore, this process was further applicable to prepare mixed phase pure perovskite crystal without PbI2impurity, and we showed that the additional merits such as extended absorption to longer wavelength, increased carrier lifetime and reduced carrier recombination could be secured.
authors: Ujwal
authors: U
authors: Thakur
authors: Division of Energy Systems Research, Ajou University, Suwon 16499, Korea.
authors: Uisik
authors: U
authors: Kwon
authors: Division of Energy Systems Research, Ajou University, Suwon 16499, Korea.
authors: Md Mehedi
authors: MM
authors: Hasan
authors: Department of Energy Science, Sungkyunkwan University, Suwon 16419, Korea.
authors: Wenping
authors: W
authors: Yin
authors: Department of Energy Science, Sungkyunkwan University, Suwon 16419, Korea.
authors: Dasom
authors: D
authors: Kim
authors: Division of Energy Systems Research, Ajou University, Suwon 16499, Korea.
authors: Na Young
authors: NY
authors: Ha
authors: Division of Energy Systems Research, Ajou University, Suwon 16499, Korea.
authors: Soonil
authors: S
authors: Lee
authors: Department of Energy Science, Sungkyunkwan University, Suwon 16419, Korea.
authors: Tae Kyu
authors: TK
authors: Ahn
authors: Division of Energy Systems Research, Ajou University, Suwon 16499, Korea.|Department Electrical and Computer Engineering, Ajou University, Suwon 16499, Korea.
authors: Hui Joon
authors: HJ
authors: Park