Paper-based ZnO ultraviolet photodetector with enhanced stability and detectivity by PTFE coatings.

The development of paper-based flexible electronic devices can reduce the use of traditional petroleum-based polymer substrates, thereby reducing environmental pollution. However, paper substrates tend to absorb moisture, which would degrade the performance of electronic devices. Polytetrafluoroethylene (PTFE) films were proposed as coatings for the paper substrate to improve the hydrophobic performance of the paper, thereby enhancing the stability of paper-based device. Hydrophobic PTFE films were deposited on both sides of the paper substrate using electron beam evaporation, which block the paper substrate from absorbing moisture. The zinc oxide (ZnO) film was sputtered onto the paper substrate and fabricated into ultraviolet photodetectors (UVPD). Numerical simulations show that the introduction of PTFE films can greatly reduce the stress from 3.21 × 10⁹ N m⁻² to 3.50 × 10⁷ N m⁻² in the ZnO epitaxial layer on the paper substrate. The stability and detectivity of the UVPD with PTFE coatings are greatly improved compared to that without PTFE coatings, providing a promising avenue for fabricating stable, superior, and sustainable paper-based electronic devices. [ABSTRACT FROM AUTHOR]