Visible to Near‐Infrared Photodetection Based on Ternary Organic Heterojunctions

Abstract

Organic semiconductors have attracted tremendous attention in the past few years, thanks to their excellent flexibility, solution-processability, low-cost, chemical versatility, etc. Particularly, organic solar cells based on ternary heterojunctions have shown remarkable device performance, with the recent development of nonfullerene acceptor materials. These novel materials are also promising for photodetection. However, there are several key limits facing organic photodetectors, such as relatively large bandgaps, poor charge transport, and stability. In this work, a novel nonfullerene acceptor-CO i 8DFIC-is introduced, blended with a fullerene derivative and a donor to form ternary heterojunctions. After optimization, photodiodes based on such ternary blends exhibit compelling performance metrics, including low dark current, decent responsivity, large linear dynamic range, fast response, and excellent stability. This device performance is actually on a par with the established silicon technology, suggesting great potential for photodetection and imaging.

Near‐infrared organic photoelectric materials for light‐harvesting systems: Organic photovoltaics and organic photodiodes

“…As aforementioned, Ding and coworkers exploited a novel NIR NFA, CO i 8DFIC, and successfully applied it to a ternary OPV with remarkable photoelectric conversion efficiency. In 2018, they introduced this promising ternary organic heterojunction into NIR OPDs with an inverted structure containing one donor (PTB7‐Th) and two acceptors (A1:CO i 8DFIC and A2:PC 71 BM) . The device performances were optimized by interfacial engineering, thermal annealing, and the construction of a thick junction, yielding a D * over 2 × 10 11 Jones in the spectral range from 400 to 1000 nm, with a peak value of 1 × 10 12 Jones (as shown in Figure ).…”

“…F, frequency response. Source : Reproduced with permission from Reference Copyright 2019, John Wiley & Sons…”

Recent Progress on Broadband Organic Photodetectors and their Applications

“…(PTB7-Th):PC 71 BM blends. [74] An inverted device was fabricated under illumination, and c) EQE spectra of the devices with varied PTB7 contents in active layer, the inset displays the energy level diagram of the used materials. Reproduced with permission.…”

An A-π-D-π-A-Type Organic Semiconductor Based Optoelectrical Device With Photo Response and Optical Memory Behaviors

“…Organic photoresponsive semiconductors have drawn tremendous attentions as an exciting candidate for photodetectors (de Arquer et al, 2017;Park et al, 2018;Li et al, 2019;Huang et al, 2020), artificial synaptic devices (Park and Lee, 2017;Dai et al, 2019;Deng et al, 2019;Yu et al, 2019;Shi et al, 2020), and particularly nonvolatile memory (Leydecker et al, 2016;Cheng et al, 2018;Liu et al, 2019;Yu et al, 2019), owing to their facile structure modification, excellent optoelectronic properties, large scale fabrication, low temperature processing, and mechanical flexibility. However, the number of semiconductors with good intrinsic optical memory behavior is small, and systematic studies on the photoresponsive semiconductors are desired.…”