# Thiol-Amine Processed PbS Thin Films for Enhanced Near-Infrared Photodetection

## TL;DR

A new method for making PbS thin films using a thiol-amine solvent system improves photodetection performance in the near-infrared range.

## Contribution

The study introduces a direct PbS thin film processing method using a thiol-amine solvent without ion-exchange steps.

## Key findings

- PbS thin films produced via the amine-thiol system show structural and optical improvements after annealing.
- Photodetectors made from these films exhibit strong photoresponse and stability.
- Directional ordering in the organic matrix during preheating leads to phase-pure PbS after annealing.

## Abstract

Developing reliable processing routes for semiconductor thin films is essential for advancing photodetection technologies. The amine-thiol solvent system, in comparison with other liquid-phase synthesis methods, does not necessitate stepwise ion-exchange reactions. It is capable of obtaining the target semiconductor thin film by directly dissolving bulk powder followed by subsequent annealing. Although PbO can be dissolved in this solvent as a raw material to obtain PbS thin films, the structural evolution, optical properties, and photodetection performance of the films obtained via this solvent system still require further exploration. This solvent system was employed to prepare PbS thin films, and a comprehensive investigation was carried out on the evolution of their structure, morphology, and optical properties during preheating and annealing treatments. During preheating, the films exhibit directional ordering within the organic matrix, which converts into phase-pure PbS upon annealing. Based on the optimized films, interdigitated photodetectors and hybrid devices integrated with graphene transistors are fabricated. The resulting devices exhibit strong photoresponse and operational stability, demonstrating the viability of amine-thiol-processed PbS films for photodetection applications.