Optimized Substrate Orientations for Highly Uniform Metal Halide Perovskite Film Deposition.

Area of Science:

• Materials Science
• Chemical Engineering
• Optoelectronics

Background:

• Uniform optoelectronic quality in metal halide perovskite (MHP) films is essential for scalable manufacturing in photovoltaics and displays.
• Vapor-based deposition offers advantages but faces challenges in achieving film uniformity due to temperature and precursor variations.

Purpose of the Study:

• To optimize substrate orientations for vapor-based fabrication of homogeneous MAPbI3 thin films.
• To investigate the impact of substrate positioning on film uniformity during PbI2 deposition and MAI conversion.

Main Methods:

• Utilized computational fluid dynamics (CFD) simulations to analyze fluid dynamics and temperature distribution.
• Employed a two-step vapor deposition process: PbI2 primary layer growth followed by MAI conversion.
• Investigated both vertical and horizontal substrate orientations for each deposition step.

Main Results:

• Vertical substrate positioning during PbI2 growth ensured uniform temperature and minimal boundary layer.
• Horizontal positioning during MAI conversion resulted in more uniform MAPbI3 thickness and grain size.
• Achieved centimeter-scale optical homogeneity and uniform optoelectronic performance in photodetector arrays.

Conclusions:

• Optimized substrate orientations, combining vertical PbI2 growth and horizontal MAI conversion, are crucial for uniform MHP film fabrication.
• This approach provides a viable pathway for the scalable production of high-quality perovskite films for optoelectronic devices.