Design and Performance of Flexible Solar-Blind Ultraviolet Photodetectors Based on Carbon Dots

Abstract

Solar-blind Ultraviolet (UV) photodetectors based on wide-bandgap semiconductors are one of the current research hotspots. However, most solar-blind UV photodetectors are based on rigid substrates, which cannot be bent and folded. Flexible UV photodetectors are attracting more and more attention due to its flexibility and portability. Its advantages of mechanical flexibility and impact resistance lay the foundation for the next generation of flexible and compatible optoelectronic devices. In this paper, planar and vertical flexible solar-blind UV photodetectors were fabricated based on carbon dots with strong absorption in the solar-blind UV region. Under 254nm UV illumination, the on/off ratio and the responsivity of the planar device is 1.15 and 0.018 mAW- <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> , respectively. The on/off ratio and the responsivity of the vertical device is 1.37 and 7.3 mAW-1, respectively. Under bending strains of 0.2%, 0.3% and 0.6%, the responsivity of the planar device is 0.019 mAW-1, 0.016 mAW-1,0.015 mAW-1, and under 0.2% bending strain, the responsivity of the vertical device is 3.7mAW-1. This has great application potential in flexible electronic devices and other fields, and provide some reference for the development of high performance flexible solar-blind deep-ultraviolet photodetectors