High‐Efficiency ZnO‐Based Ultraviolet Photodetector with Integrated Single‐Walled Carbon Nanotube Thin‐Film Heater

Abstract

Recently, sol–gel‐derived ZnO thin films have been explored for high performance photodetectors (PDs). However, the crystallinity of sol–gel‐derived ZnO films is inferior to vacuum‐based grown ZnO film, leading to poor photoreaction in the PDs. This study combines a single‐walled carbon nanotube (SWCNT) heating system with sol–gel ZnO‐based ultraviolet (UV) PDs. A SWCNT heater is fabricated on sapphire substrates using spin coating technique, resulting in a transparent heater with a transmittance of ≈80% by controlling spin speed. In addition, increasing the number of SWCNT spin coatings from 1 to 3 raises the heater temperature to over 170 °C, resulting in a response time of less than 1 min. The sol–gel ZnO‐based UV PDs with the SWCNT heater shows a 137% increase in photocurrent as the SWCNT heater temperature increases from 25 to 112 °C. In addition, the increase in temperature of the embedded‐SWCNT heater significantly shortens the rise and decay times of the sol–gel‐derived ZnO PDs.

Recent Advances in Solution-Processed Zinc Oxide Thin Films for Ultraviolet Photodetectors

“…Recently, Alwadai et al fabricated a solar-blind UV-C PD array using solution-processed n-ZnO quantum dots (QDs) functionalized with p-CuO micropyramids, which exhibited a high responsivity of 29 mA/W . Kim et al investigated the effect of temperature on ZnO thin films because it controls the rate of adsorption and desorption of oxygen molecules onto the surface . Also, Majumdar et al explored the addition of graphene oxide (GO) to the ZnO growth medium to realize ZnO nanoflakes.…”