Cost-Effective and Flexible Scalable Fabrication of WO₃ UV Photodetectors with Enhanced Performance via Integrated LIG Electrodes

The emerging flexible device technologies have fascinated the modern optoelectronic industry owing to their invincible properties such as wearable, stretchable, smart, energy-efficient, scalability, cost-effective, and high performance. However, there is still room for improvements such as performance, reliability, and mass production. This research work fabricates laser-induced graphene (LIG) interdigitated electrodes based on flexible UV photodetectors over polyimide substrate, using solution-processed tungsten oxide (WO₃) thin film as photoactive material. The best device performance is achieved through the optimization of laser power for the deposition of LIG, as well as a different solvent for WO₃. The device shows excellent photoresponsivity, external quantum efficiency, and specific detectivity of 500 mA W⁻¹, 164%, and 3.09 × 10¹² Jones, respectively. Moreover, a fast response time, such as 0.3 ms for 375 nm light, is observed. This study offers a comprehensive elucidation of the intricate process through which photoelectrons are moved toward WO₃ facilitated by the electric field present at the interface of the LIG and WO₃.