Single- vs dual-source vapor deposition of inorganic halide perovskites: A case study of CsPbBr₃

Single- vs dual-source vapor deposition of inorganic halide perovskites: A case study of CsPbBr₃

Článek WoS

Inorganic halide perovskites have become attractive for many optoelectronic applications due to their outstanding properties. While chemical synthesis techniques have been successful in producing high-quality perovskite crystals, scaling up to wafer-scale thin films remains challenging. Vapor deposition methods, particularly physical vapor deposition and chemical vapor deposition, have emerged as potential solutions for large-scale thin film fabrication. However, the control of phase purity during deposition remains problematic. Here, we investigate single-source (CsPbBr3) and dual-source (CsBr and PbBr2) physical vapor deposition techniques with the aim of achieving phase-pure CsPbBr3 thin films. Utilizing Knudsen effusion mass spectrometry, we demonstrate that while the single-source CsPbBr3 evaporation is partially congruent, it leads to compositional changes in the evaporant over time. The dual-source evaporation, with a precise control of the PbBr2/CsBr flux ratio, can improve phase purity, particularly at elevated substrate temperatures under excess PbBr2 conditions. Our results give direct evidence that the growth is CsBr-limited. Overall, our findings provide critical insights into the vapor phase deposition processes, highlighting the importance of evaporation conditions in achieving the desired inorganic perovskite stoichiometry and morphology. (c) 2025 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

Inorganic halide perovskites have become attractive for many optoelectronic applications due to their outstanding properties. While chemical synthesis techniques have been successful in producing high-quality perovskite crystals, scaling up to wafer-scale thin films remains challenging. Vapor deposition methods, particularly physical vapor deposition and chemical vapor deposition, have emerged as potential solutions for large-scale thin film fabrication. However, the control of phase purity during deposition remains problematic. Here, we investigate single-source (CsPbBr3) and dual-source (CsBr and PbBr2) physical vapor deposition techniques with the aim of achieving phase-pure CsPbBr3 thin films. Utilizing Knudsen effusion mass spectrometry, we demonstrate that while the single-source CsPbBr3 evaporation is partially congruent, it leads to compositional changes in the evaporant over time. The dual-source evaporation, with a precise control of the PbBr2/CsBr flux ratio, can improve phase purity, particularly at elevated substrate temperatures under excess PbBr2 conditions. Our results give direct evidence that the growth is CsBr-limited. Overall, our findings provide critical insights into the vapor phase deposition processes, highlighting the importance of evaporation conditions in achieving the desired inorganic perovskite stoichiometry and morphology. (c) 2025 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

SOLAR-CELLS; VACUUM DEPOSITION; EPITAXIAL-GROWTH; FILMS; CSPBX3; BR; CL

SOLAR-CELLS; VACUUM DEPOSITION; EPITAXIAL-GROWTH; FILMS; CSPBX3; BR; CL

Musálek, T.; Liska, P.; Morsa, A.; Arregi, JA.; Klok, P.; Kratochvil, M.; Sergeev, D.; Müller, M.; Sikola, T.; Kolibal, M.

01.03.2025

AIP Publishing

MELVILLE

2166-532X

APL Materials

13

3

Spojené státy americké

10

https://pubs.aip.org/aip/apm/article/13/3/031118/3340729/Single-vs-dual-source-vapor-deposition-of