Effects of Oxalic Acid on UV-C Sensing Property of Tomato Thin-Film Based Photodetector

摘要

New concept of UV photodetector with self-powered and biodegradable features are needed to solve energy and environment. In this work, tomato thin-film was used as an active organic layer in UV photodetector. The effect of oxalic acid in the extraction of tomato juice on the formation of a solid thin film that dried at 120°C for 30 min has been investigated. The purpose of adding oxalic acid is to extract ascrobic acid from tomato. A comparison between tomato juice extracted with and without oxalic acid on the structural, chemical, optical, electrical and UV sensing properties of tomato thin-film have been investigated. The UV photodetector was consisted of a sandwich structure of glass substrate/tomato thin-film/interdigitated aluminium electrode. The photodetector operated at 5 V with tomato thin-film extracted from tomato juice with oxalic acid revealed the highest responsivity percentage difference (89.60%) in UV-C with quantum efficiency (η) of 1.0335x10-5 %, responsivity (R) of 2.1178x10-6 A/W, and detectivity (D*) of 1.1649x1021 Jones. While without oxalic acid, the highest responsivity percentage difference (70.6%) in UV-C was operated at 0 V.