Lead free perovskite based heterojunction photodetectors: A mini review
Swayam Aryam Behera, P. Ganga Raju Achary
Abstract
In recent years, heterojunction photodetectors have been proposed as promising optoelectronics. The heterojunction photodetectors have garnered attention on a global scale due to its crucial role in both public or commercial applications and basic scientific research. The study of heterojunction photodetector offers new opportunities and important insights for the development of photodetectors because of exceptional mechanical stability, excellent photoelectronic properties and a unique synergistic effect. Photodetectors (PDs) are an essential type of optoelectronic device, transform photons into electric signals. These are widely utilised in a variety of disciplines; including imaging, infrared detection, polarisation detection, optical communication, and environmental and health monitoring. To generate electrical field for enhancing collection efficiency and suppressing the recombination of photo generated carriers, heterojunctions are developed in order to realise high performance photodetectors. The effectiveness of the aforementioned optoelectronic systems will be significantly influenced by the PD's detecting performance. A popular method for enhancing the performance of PDs is to build semiconductor heterojunctions by fusing two different kinds of semiconducting phases. A number of inorganic hole transport layers (HTL) such as; Cu2O, CuI, NiOX etc.) and electron transport layers (ETL) such as; ZnO, SnO2, TiO2 etc.) are designed to suppress carrier recombination and make better photocarriers separation due to the formation of the built-in electrical field. This helps the researchers to fabricate heterojunction using perovskite, while simultaneously improving the stability. A promising alternative to the conventional lead-based hybrid perovskites in the realm of photoelectric detection devices is the lead-free all-inorganic halide perovskite. This study can provide new possibilities for the future of heterojunction PDs due to excellent photoelectric properties, a unique synergistic effect, and outstanding mechanical stability. This paper comprises recent years of lead-free perovskite high performance heterojunction photodetector including dark current, photoresponsivity, detectivity. It also covers important topics such as methods of preparation of lead-free perovskites, materials suitable for photodetectors and fabrication of heterojunctions which will open up new possibilities and encourage further work to fully realise heterojunction's potential. Important information about heterojunctions and materials appropriate for self-powered photodetectors is also highlighted. This article concludes with possible future developments in this dynamic and fast evolving field.