A photodetector fabricated from 2H-PbI2 micro-crystals recycled from waste lead acid batteries

Recycling Pb from lead acid batteries is rather important in environmental protection, but current strategies need a high temperature or produce secondary pollution. Herein, we present a green reactant recycling method to synthe-size PbI2 micro-crystals by extracting the Pb from waste lead acid batteries. Systematical characterizations indicate that the as-prepared PbI2 micro-crystals show high purity, high crystal quality with a 2H-hexagonal crystal structure, and excellent optical properties with a bandgap of 2.3 eV. Based on the recycled 2H-PbI2 micro-crystals, a symmetri-cally structured ITO/PbI2/ITO photodetector is fabricated. Under 10 V bias voltage, the device reveals a distinct photo -response to UV-visible light and superior performance, with a dark current of 1.06 nA, an on-off ratio of 103, a responsiv-ity of 15.5 mA/W, and a detectivity of 4.7 x 1010 Hz1/2 W-1. In addition, the photodetector also exhibits relatively rapid response speeds of 69 ms (rise time) and 64 ms (decay time). Our study provides an innovative and green strategy for pro-ducing a UV-visible photodetector based on recycled lead acid batteries, which is significant in environmental pro-tection and the recycling economy. (c) 2023 Optica Publishing Group

Automated summary

In this study, PbI2 micro-crystals with high purity and crystal quality were successfully synthesized by recycling Pb from waste lead acid batteries. A photodetector based on the recycled PbI2 micro-crystals showed superior performance and relatively rapid response speeds. This innovative and green strategy for producing a UV-visible photodetector from recycled lead acid batteries is significant in environmental protection and the recycling economy.