A Framework for Designing Efficient Eco-Friendly Broadband GeSn/SnS Photodetector Based on Light Trapping Engineering

A multispectral photoresponse feature of a self-powered photodetector device is quickly becoming a key technology to address the scaling challenges in emerging multifunctional optoelectronic systems. The heterostructure of different materials has opened new pathways to design broadband self-driven photoresponse using a single device. In this work, a new multispectral photodetector based on SnS/GeSn heterostructure with optimized gold nanoparticles is proposed. Moreover, broadband photodetector performances are improved by using a new design framework based on coupling particle swarm optimization approach and plasmonic effects. Numerical models based on the finite difference time domain method are carried out. A broadband photodetection is achieved in a single SnS/GeSn heterostructured photodetector with optimized surface gold nanoparticles, with a high on/off ratio of 160 dB, improved responsivity of 8.5 A/W and specific detectivity of over 5 × 10¹² Jones in the self-powered mode. Therefore, the proposed design framework based on the strategic combination between SnS/GeSn heterostructure and optimized gold nanoparticles array provides new paths and efficient strategy to enhance the optoelectronic performance of broadband photodetectors by exploiting the light trapping engineering combined with band-gap tuning aspects.