Grain engineering of solution-processed Sb2S3 thin film by tuning precursor fabrication environments

Abstract

Antimony sulfide (Sb2S3) has garnered significant attention recently due to its remarkable photovoltaic properties and low toxicity. However, the conventional physical vapor deposition approach faces challenges in achieving high-quality films due to Sb2S3 having a quasi-one-dimensional nanoribbon structure. In contrast, solution-processed Sb2S3 thin films have shown improved photovoltaic behavior, offering a low-cost and scalable fabrication method. Nonetheless, the sensitivity of the solution process to the chemical composition of the precursor poses a challenge, often requiring noble gas protection to prevent exposure to toxic solvents or moisture-sensitive chemicals. Despite this, the impact of precursor fabrication conditions on film growth behavior remains unexplored. In our study, we investigate how different processing atmospheres of precursors, namely nitrogen (N2) and air, affect grain growth and the associated optical and electronic performance of Sb2S3 thin films. Our findings reveal that the presence of oxygen in the precursor can hinder grain growth by obstructing surface integration sites, resulting in undesired (hk0) orientation and even the formation of Sb2O3 on the surface of the Sb2S3 films, despite identical post-deposition conditions. This research sheds light on how the ambient conditions during precursor preparation can influence grain engineering, thereby providing valuable insights for controlling the grain size and producing high-quality Sb2S3 absorber films.