Novel Physical Vapor Deposition Approach to Hybrid Perovskites: Growth of MAPbI3 Thin Films by RF-Magnetron Sputtering

Sara Bonomi,Giovanni Bongiovanni,Maddalena Patrini,Michele Saba,Nicola Sestu,Lorenzo Malavasi,Daniela Marongiu

doi:10.1038/s41598-018-33760-w

Abstract

Solution-based methods represent the most widespread approach used to deposit hybrid organic-inorganic perovskite films for low-cost but efficient solar cells. However, solution-process techniques offer limited control over film morphology and crystallinity, and most importantly do not allow sequential film deposition to produce perovskite-perovskite heterostructures. Here the successful deposition of CH3NH3PbI3 (MAPI) thin films by RF-magnetron sputtering is reported, an industry-tested method to grow large area devices with precisely controlled stoichiometry. MAPI films are grown starting from a single-target made of CH3NH3I (MAI) and PbI2. Films are single-phase, with a barely detectable content of unreacted PbI2, full surface coverage and thickness ranging from less than 200 nm to more than 3 μm. Light absorption and emission properties of the deposited films are comparable to as-grown solution-processed MAPI films. The development of vapor-phase deposition methods is of interest to advance perovskite photovoltaic devices with the possibility of fabricating perovskite multijunction solar cells or multicolor bright light-emitting devices in the whole visible spectrum.

Highlights

Solution-based methods represent the most widespread approach used to deposit hybrid organicinorganic perovskite films for low-cost but efficient solar cells
The vapor-based methods applied to the synthesis of hybrid perovskites are mainly based on vacuum evaporation process and vapor-assisted solution processes (VASP), with few other attempts of flash evaporation and ultrasonic spray coating[7,8]
Motivated by the above reported issues related to the preparation of hybrid organic-inorganic perovskites films, in this paper we demonstrate the successful one-pot growth of methylammonium lead iodide CH3NH3PbI3 (MAPI) films by means of RF-magnetron sputtering starting from a single target made of a CH3NH3I (MAI) and PbI2 mixture with a 30% w/w excess of made of CH3NH3I (MAI)

Summary

Introduction

Solution-based methods represent the most widespread approach used to deposit hybrid organicinorganic perovskite films for low-cost but efficient solar cells. A very promising alternative to solution-based methods are the vapor-based deposition techniques, which started in the last few years to attract significant interest as a possible route to overcome the aforementioned problems[6,7,8,9]. These methods are expected to provide purity of precursors and deposited films due to the vacuum environment and fine control of the deposition parameters, resulting in a high level of perovskite crystallization and reproducible films. No reports about the deposition of hybrid perovskites thin films by sputtering has been reported

Methods

Results

Conclusion