Efficient Wide-Bandgap Mixed-Cation and Mixed-Halide Perovskite Solar Cells by Vacuum Deposition.

Lidón Gil-Escrig,Zafer Hawash,Steve Albrecht,Henk J Bolink,Chris Dreessen,Michele Sessolo,Ellen Moons,Francisco Palazon

doi:10.1021/acsenergylett.0c02445

Lidón Gil-Escrig, Zafer Hawash + Show 6 more

Open Access

PDF Available

https://doi.org/10.1021/acsenergylett.0c02445

Copy DOI

Export

Save

Cite

Abstract
Highlights/Summary
Full-Text PDF
Similar Papers

Abstract

Listen

Vacuum deposition methods are increasingly applied to the preparation of perovskite films and devices, in view of the possibility to prepare multilayer structures at low temperature. Vacuum-deposited, wide-bandgap solar cells based on mixed-cation and mixed-anion perovskites have been scarcely reported, due to the challenges associated with the multiple-source processing of perovskite thin films. In this work, we describe a four-source vacuum deposition process to prepare wide-bandgap perovskites of the type FA1–nCsnPb(I1–xBrx)3 with a tunable bandgap and controlled morphology, using FAI, CsI, PbI2, and PbBr2 as the precursors. The simultaneous sublimation of PbI2 and PbBr2 allows the relative Br/Cs content to be decoupled and controlled, resulting in homogeneous perovskite films with a bandgap in the 1.7–1.8 eV range and no detectable halide segregation. Solar cells based on 1.75 eV bandgap perovskites show efficiency up to 16.8% and promising stability, maintaining 90% of the initial efficiency after 2 weeks of operation.

Highlights

Vacuum deposition methods are increasingly applied to the preparation of perovskite films and devices, in view of the possibility to prepare multilayer structures at low temperature
A mong emerging photovoltaic (PV) technologies, thinfilm solar cells based on organic−inorganic lead halide perovskites are by far the most widely investigated. The interest toward these materials is driven by the possibility to deposit high-quality semiconducting films with simple and low-energy-demanding processes.[1−6] This feature is a consequence of the high tolerance to defects,[7,8] conferring perovskites with low trap density and long carrier diffusion length.[9−14] As a result, the efficiency of single-junction solar cells has grown considerably within only a decade of development,[15] with a record power conversion efficiency (PCE) exceeding 25%
Vacuum deposition is an alternative method with superior control over the film thickness and composition; it is compatible with large areas and eliminates the processing concerns related with the use of solvents.[61−63] This is especially relevant for the fabrication of complex multilayer architectures, necessary for tandem solar cells.[37,64]

Summary

Introduction

Vacuum deposition methods are increasingly applied to the preparation of perovskite films and devices, in view of the possibility to prepare multilayer structures at low temperature. The simultaneous sublimation of the two lead halides allows the relative bromide/cesium content to be decoupled and controlled, resulting in homogeneous perovskite films with a bandgap in the 1.7−1.8

Results

Conclusion