Controllable deposition of organic metal halide perovskite films with wafer-scale uniformity by single source flash evaporation
Woo‐Cheol Lee, Jonghoon Lee, Hyeon-Dong Lee, Junwoo Kim, Heebeom Ahn, Youngrok Kim, Daekyoung Yoo, Jeongjae Lee, Tae‐Woo Lee, Keehoon Kang, Takhee Lee, Takhee Lee, Takhee Lee
Abstract
Abstract Conventional solution-processing techniques such as the spin-coating method have been used successfully to reveal excellent properties of organic–inorganic halide perovskites (OHPs) for optoelectronic devices such as solar cell and light-emitting diode, but it is essential to explore other deposition techniques compatible with large-scale production. Single-source flash evaporation technique, in which a single source of materials of interest is rapidly heated to be deposited in a few seconds, is one of the candidate techniques for large-scale thin film deposition of OHPs. In this work, we investigated the reliability and controllability of the single-source flash evaporation technique for methylammonium lead iodide (MAPbI 3 ) perovskite. In-depth statistical analysis was employed to demonstrate that the MAPbI 3 films prepared via the flash evaporation have an ultrasmooth surface and uniform thickness throughout the 4-inch wafer scale. We also show that the thickness and grain size of the MAPbI 3 film can be controlled by adjusting the amount of the source and number of deposition steps. Finally, the excellent large-area uniformity of the physical properties of the deposited thin films can be transferred to the uniformity in the device performance of MAPbI 3 photodetectors prepared by flash evaporation which exhibited the responsivity of 51 mA/W and detectivity of 9.55 × 10 10 Jones.