Real-Time Ultraviolet Monitoring System with Low-Temperature Solution-Processed High-Transparent p–n Junction Photodiode with a Fast Responsive and High Rectification Ratio

• Published in: ACS applied materials & interfaces 2024-07, Vol.16 (30), p.40139-40148
• Main Authors: Ha, Hyoun Ji, Kang, Seong Jae, Jeong, Jun Hyung, Ma, Jin Hyun, Park, Min Ho, Kim, Wonsik, Ha, Aelim, Kim, Seunghwan, Park, Soohyung, Kang, Seong Jun
• Format: Article
• Language: English
• Subjects: signal-to-noise ratio; standard deviation; Surfaces, Interfaces, and Applications; temperature
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/acsami.4c05494

We introduce an enhanced performance organic–inorganic hybrid p–n junction photodiode, utilizing poly­[bis­(4-phenyl) (2,4,6-trimethylphenyl)­amine] (PTAA) and ZnO, fabricated through a solution-based process at a low temperature under 100 °C. Improved interfacial electronic structure, characterized by shallower Gaussian standard deviation of the density-of-state distribution and a larger interface dipole, has resulted in a remarkable fold increase of ∼102 in signal-to-noise ratio for the device. This photodiode exhibits a high specific detectivity (2.32 × 1011 Jones, cm × Hz × W − 1 ) and exceptional rectification ratio (5.47 × 104 at ±1 V). The primary light response, concentrated in the optimal thickness of the PTAA layer, contributes to response over the entire UVA region and rapid response speed, with rise and fall times of 0.24 and 0.64 ms, respectively. Furthermore, this work demonstrates immense potential of our device for health monitoring applications by enabling real-time and continuous measurements of UV intensity.