Two-Step Synthesis of Bismuth-Based Hybrid Halide Perovskite Thin-Films.

Vanira Trifiletti,Oliver Fenwick,William P. Gillin,Simona Binetti,Sally Luong,Giorgio Tseberlidis,Eugenio S. S. Galindez,Stefania Riva

doi:10.3390/ma14247827

Vanira Trifiletti, Oliver Fenwick + Show 6 more

Open Access

https://doi.org/10.3390/ma14247827

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Abstract

Lead halide perovskites have been revolutionary in the last decade in many optoelectronic sectors. Their bismuth-based counterparts have been considered a good alternative thanks to their composition of earth-abundant elements, good chemical stability, and low toxicity. Moreover, their electronic structure is in a quasi-zero-dimensional (0D) configuration, and they have recently been explored for use beyond optoelectronics. A significant limitation in applying thin-film technology is represented by the difficulty of synthesizing compact layers with easily scalable methods. Here, the engineering of a two-step synthesis in an air of methylammonium bismuth iodide compact thin films is reported. The critical steps of the process have been highlighted so that the procedure can be adapted to different substrates and application areas.

Highlights

Bismuth-based hybrid halide perovskites are composed of elements widely available from natural sources and show improved chemical stability and less toxicity compared to their lead-based counterparts [1,2,3,4,5]
Bismuth-based perovskites have emerged as a new research field, being explored for use in solar cells; the results obtained have not led to improvements in the state-of-the-art, due to the poor substrate coverage and to the charge confinement that limit their use in photovoltaics [3,6]
Encouraging results on (CH3NH3)3Bi2I9 (MABI) deposition were obtained using two-step depositions on mesoporous TiO2 [17], where the BiI3 layer is dipped in a CH3NH3I (MAI) solution to complete the synthesis

Summary

Introduction

Bismuth-based hybrid halide perovskites are composed of elements widely available from natural sources and show improved chemical stability and less toxicity compared to their lead-based counterparts [1,2,3,4,5] For these reasons, bismuth-based perovskites have emerged as a new research field, being explored for use in solar cells; the results obtained have not led to improvements in the state-of-the-art, due to the poor substrate coverage and to the charge confinement that limit their use in photovoltaics [3,6]. In order to produce a compact layer, BiI3 was deposited by thermal evaporation of commercial powders, while MAI was introduced by dipping in a solution in isopropyl alcohol (IPA). This work defines a procedure developed and performed in air with optimised dipping and annealing times, leading to thick and compact films on flat substrates

Materials

Synthesis of MABI Thin Films

Characterization

Results and Discussion