Broadband photomultiplication organic photodetectors

• Published in: Physical chemistry chemical physics : PCCP Vol. 23; no. 4; pp. 2923 - 2929
• Main Authors: Liu, Meng-yao, Wang, Jian, Yang, Kai-xuan, Liu, Ming, Zhao, Zi-jin, Zhang, Fu-jun
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 04.02.2021
• Subjects: Broadband; Charge transport; Circuits; Mathematical analysis; Photometers; Quantum efficiency
• ISSN: 1463-9076; 1463-9084; 1463-9084
• DOI: 10.1039/d0cp05811d

Broadband photomultiplication organic photodetectors (PMOPDs) can be achieved with a double-layered active layer prepared from IEICO-4F : PBDB-T blend solutions with different weight ratios (1 : 1 or 3 : 100, wt/wt). The response range of the double-layered PMOPDs covers from 310 nm to 930 nm, determined by the photon harvesting range of the IEICO-4F : PBDB-T (1 : 1, wt/wt) layer. The IEICO-4F : PBDB-T (3 : 100, wt/wt) layer was used as a PM layer in the double-layered PMOPDs, achieving external quantum efficiency (EQE) more than 100% based on the work mechanism of trap-assisted hole tunneling injection. The trapped electrons in PBDB-T/IEICO-4F/PBDB-T near the Al electrode will makeinterfacial-band-bending to narrow the injection barrier, resulting in hole-tunneling-injection from the external circuit. The polymer PBDB-T can provide an efficient charge transport channel for the injected hole from the external circuit. The specific detectivity ( D *) and responsivity ( R ) of the double-layered PMOPDs are 1.05 ± 0.03 × 10 12 Jones and 0.94 ± 0.03 A W −1 at 810 nm under a −10 V bias, respectively. Broadband photomultiplication type organic photodetectors (PM-OPDs) were successfully fabricated by employing a double-layered scheme with a photon harvesting layer and a PM layer.