Negative photoconductivity in low-dimensional materials*

In recent years, low-dimensional materials have received extensive attention in the field of electronics and optoelectronics. Among them, photoelectric devices based on photoconductive effect in low-dimensional materials have a broad development space. In contrast to positive photoconductivity, negative photoconductivity (NPC) refers to a phenomenon that the conductivity decreases under illumination. It has novel application prospects in the field of optoelectronics, memory, and gas detection, etc. In this paper, we review reports about the NPC effect in low-dimensional materials and systematically summarize the mechanisms to form the NPC effect in existing low-dimensional materials.