A Flexible Self-Powered UV Photodetector and Optical UV Filter Based on β-Bi2O3/SnO2 Quantum Dots Schottky Heterojunction

Recently reported ultraviolet (UV) detectors majorly focus on exploration of photodetection properties like photon absorption and electron-hole pair generation to improve the photoresponsivity. However, UV sensors also have a potential advantage of monitoring the excessive UV exposure on skin. In this work, bismuth oxide/SnO2 quantum dots (QDs) vertical-junction-based self-powered UV photodetector and optical UV filter are demonstrated. beta-Bi2O3 nanofibers are synthesized via electrospinning technique and SnO2 QDs are synthesized using a facile, single step hydrothermal process. Detailed morphological studies reveal the formation of 1D-Bi2O3 and 0D-SnO2. The fabricated self-powered Bi2O2/SnO2-based p-n heterojunction device exhibits a maximum responsivity of 62.5 mu A W-1 and specific detectivity (D*) of 4.5 x 109 Jones attributing to the high absorption coefficient of beta-Bi2O2 nanofibers and SnO2 QDs in the UV region. Further, the 1D beta-Bi2O3 nanofibers and 0D SnO2 QDs are coated onto disposable cloth substrate to fabricate the UV optical filter which exhibits an exceptional ultraviolet protection factor of 159 and the photodetector device demonstrates high stability and reproducibility even after 1000 bending cycles. The strategy outlined here paves the way for development of bifunctional, cost-effective design and construction of wearable UV sensors and protective devices for advanced nano-electronic applications.

Automated summary

The study demonstrates a self-powered UV photodetector and optical UV filter based on Bi2O2/SnO2 which exhibit high responsivity and specific detectivity. The UV optical filter, coated on cloth substrate, shows exceptional ultraviolet protection factor. This strategy lays the foundation for the development of cost-effective wearable UV sensors and protective devices.