講演情報
[19p-D902-5]Photostable ultraflexible organic photodiodes using a hybrid electron transport layer
〇Theodorus Jonathan Wijaya1, Sixing Xiong2, Sunghoon Lee1, Kenjiro Fukuda2, Tomoyuki Yokota1, Takao Someya1,2 (1.UTokyo EEIS, 2.Riken CEMS)
キーワード：
organic photodetector、electron transport layer、stability
Organic photodiodes (OPDs) achieved high figures of merit which enabled their applications as wearables in biomedical settings. However, the detectivity of OPDs is unstable with respect to strong light irradiation where dark current in OPDs increases by several orders of magnitude. Here, OPDs with initially low dark current values and a nearly identical value after irradiation were accomplished by using a novel ZnO-based hybrid electron transport layer (ETL) at a low process temperature (180oC). Specifically, we used PEIZn NP, made by mixing ZnO nanoparticle (NP) ETL and ethoxylated polyethyleneimine (PEIE) polymer. Employing “glass/ITO/PEIZn NP/P3HT:PC61BM/MoOx/Ag” structure, the OPDs exhibited an initial dark current density of (3.6 ± 0.38) × 10-8 A/cm2, which increased only by 1.3 times to (4.5 ± 0.32) × 10-8 A/cm2 after light irradiation – equivalent to 89% stability in detectivity. In addition, the OPD on 1-µm parylene substrate showed mechanical ultraflexibility. After 5000 bending cycles, the photocurrent decreases only by 8.1% and its dark current remained less than 7.0×10-7 A/cm2. This work paves the way for a stable photodetector wearable.