AUTHOR=Feng Shiyu , Dai Donghuan , Lin Yao , Chen Shuo , Wu Xiaosong , Huang Weiguo 

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

JOURNAL=Frontiers in Materials

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2020.567031

DOI=10.3389/fmats.2020.567031

ISSN=2296-8016

ABSTRACT=<p>A novel photoactive semiconductor (named as IDTOT-4F) with an A-π-D-π-A-type configuration is synthesized. It contains an electron-donating fused ring (D) as the core flanked with two π-spacers and is end-capped with two electron-withdrawing units (A). The intramolecular charge transfer effect endows IDTOT-4F with strong and broad light absorption and a relatively narrow band gap (1.46 eV). Thin-film optoelectrical devices based on IDTOT-4F exhibit both <italic>n</italic>-type and <italic>p</italic>-type switching behaviors. Besides, the <italic>p</italic>-channel device shows significantly photoresponsive performance with the maximum <italic>P</italic> (photo/dark current ratio), <italic>R</italic> (photoresponsivity), and <italic>D*</italic> (detectivity) values of around 60, 0.07 AW<sup>−1</sup>, and 2.5 × 10<sup>10</sup> Jones, respectively. Further, IDTOT-4F based optoelectrical devices exhibit good optical memory characteristics with a time constant <italic>τ</italic><sub>1</sub> of 4.6 h, indicating its applicability to nonvolatile optical memory devices. The results provide new insights into the photoresponsive behavior of fused-ring semiconductors and pave the way for the design of nonvolatile optical memory devices.</p>