Effects of Asymmetric Source-Drain Electrodes and Their Modifications on the Operation of Organic Phototransistors

• Published in: IEEE electron device letters Vol. 44; no. 1; pp. 92 - 95
• Main Authors: Jiang, Chaoqun, Liu, Chen, Hu, Gang, Wang, Xinyu, Zhang, Ningbo, Hu, Yang, Cai, Shengliang, Tang, Chenyu, Liu, Dongqi, Peng, Yingquan, Xu, Sunan, Sun, Lei, Lv, Wenli
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-01-2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Asymmetry; Buffer layers; Charge injection; Electrodes; Field effect transistors; Gold; Logic gates; Optimized production technology; Optoelectronic devices; Pentacene; Performance evaluation; photodetectors; Phototransistors; Quantum efficiency; Semiconductor devices; Silver
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2022.3225822

Asymmetric source and drain (S-D) electrodes and their interfacial modifications have significant effects on the charge injection and transport in organic field-effect transistors, however their effects on the operation and performance of organic phototransistors (OPTs) are unknown. Herein, OPTs with symmetric (Ag-Ag, Au-Au) and asymmetric (Au-Ag, Au-bathocuproine (BCP)/Ag, Au/MoO3-BCP/Ag) S-D electrodes were fabricated and their performances were investigated. The results demonstrated that the devices with asymmetric S-D electrodes are superior than their counterparts with symmetric S-D electrodes. Among the three devices with asymmetric S-D electrodes Au-BCP/Ag device exhibits the highest photo responsivity of 36.6 A/W and external quantum efficiency of 7000%, meanwhile Au-BCP/Ag and Au/MoO3-BCP/Ag device exhibit significantly larger specific detectivity than Au-Ag device. The result gives an important guideline for designing high performance OPTs.