Influence of chemical interactions on the electronic properties of BiOI/organic semiconductor heterojunctions for application in solution-processed electronics

TL;DR

This study explores BiOI/organic semiconductor heterojunctions fabricated via solution processing, revealing their potential in low-cost, environmentally friendly electronic devices with improved properties for optoelectronic applications.

Contribution

It demonstrates the successful integration of solution-processed BiOI thin films into heterojunction FETs, highlighting chemical interactions at interfaces that enhance device performance.

Findings

BiOI/OSC heterojunctions show significant threshold voltage shifts.

Hybrid devices retain carrier mobility similar to pristine OSC devices.

First successful incorporation of solution-processed BiOI in three-terminal devices.

Abstract

Bismuth oxide iodide (BiOI) has been viewed as a suitable environmentally-friendly alternative to lead-halide perovskites for low-cost (opto-)electronic applications such as photodetectors, phototransistors and sensors. To enable its incorporation in these devices in a convenient, scalable, and economical way, BiOI thin films were investigated as part of heterojunctions with various p-type organic semiconductors (OSCs) and tested in a field-effect transistor (FET) configuration. The hybrid heterojunctions, which combine the respective functionalities of BiOI and the OSCs were processed from solution under ambient atmosphere. The characteristics of each of these hybrid systems were correlated with the physical and chemical properties of the respective materials using a concept based on heteropolar chemical interactions at the interface. Systems suitable for application in lateral transport devices were identified and it was demonstrated how materials in the hybrids interact to provide improved and synergistic properties. These indentified heterojunction FETs are a first instance of successful incorporation of solution-processed BiOI thin films in a three-terminal device. They show a significant threshold voltage shift and retained carrier mobility compared to pristine OSC devices and open up possibilities for future optoelectronic applications.