Lead sulphide nanocrystal photodetector technologies

Light detection is the underlying principle of many optoelectronic systems. For decades, semiconductors including silicon carbide, silicon, indium gallium arsenide and germanium have dominated the photodetector industry. They can show excellent photosensitivity but are limited by one or more aspects, such as high production cost, high-temperature processing, flexible substrate incompatibility, limited spectral range or a requirement for cryogenic cooling for efficient operation. Recently lead sulphide (PbS) nanocrystals have emerged as one of the most promising new materials for photodetector fabrication. They offer several advantages including low-cost manufacturing, solution processability, size-tunable spectral sensitivity and flexible substrate compatibility, and they have achieved figures of merit outperforming conventional photodetectors. We review the underlying concepts, breakthroughs and remaining challenges in photodetector technologies based on PbS nanocrystals.

光探测是许多光电系统的基本原理。几十年来，包括碳化硅、硅、砷化铟镓和锗在内的半导体在光电探测器行业占据主导地位。它们可以表现出优异的光敏性，但受到一个或多个方面的限制，例如生产成本高、高温加工、与柔性基底不兼容、光谱范围有限或为了高效运行需要低温冷却。最近，硫化铅（PbS）纳米晶体已成为制造光电探测器最有前途的新材料之一。它们具有多种优势，包括低成本制造、溶液可加工性、尺寸可调的光谱灵敏度以及与柔性基底的兼容性，并且它们取得的性能指标优于传统光电探测器。我们综述了基于硫化铅纳米晶体的光电探测器技术的基本概念、突破以及仍然存在的挑战。