Preparation of CH3NH3PbI3 thin films with tens of micrometer scale at high temperature

TL;DR

This paper introduces a high-temperature chemical vapor reaction method to produce large-scale CH3NH3PbI3 perovskite films with improved grain size, enhancing solar cell performance with notable current density and efficiency.

Contribution

A novel high-temperature vapor reaction technique for fabricating large-grain CH3NH3PbI3 films suitable for high-efficiency perovskite solar cells.

Findings

Grain size increased from ~1 μm to over 10 μm with temperature.

Pure phase CH3NH3PbI3 confirmed by X-ray diffraction.

Solar cells achieved a short-circuit current density of 15.75 mA/cm2.

Abstract

The fabrication of high-quality organic-inorganic hybrid halide perovskite layers is the key prerequisite for the realization of high efficient photon energy harvest and electric energy conversion in their related solar cells. In this article, we report a novel fabrication technique of CH3NH3PbI3 layer based on high temperature chemical vapor reaction. CH3NH3PbI3 layers have been prepared by the reaction of PbI2 films which were deposited by pulsed laser deposition, with CH3NH3I vapor at various temperatures from 160 oC to 210 oC. X-ray diffraction patterns confirm the formation of pure phase, and photoluminescence spectra show the strong peak at around 760 nm. Scanning electron microscopy images confirm the significantly increased average grain size from nearly 1 {\mu}m at low reaction temperature of 160 oC to more than 10 {\mu}m at high reaction temperature of 200 oC. The solar cells were fabricated, and short-circuit current density of 15.75 mA/cm2, open-circuit voltage of 0.49 V and fill factor of 71.66% have been obtained.