Dipolar donor–acceptor molecules in the cyanine limit for high efficiency green-light-selective organic photodiodes. Issue 5 (13th January 2016)

• Record Type: Journal Article
• Authors: Bulliard, Xavier; Jin, Yong Wan; Lee, Gae Hwang; Yun, Sungyoung; Leem, Dong-Seok; Ro, Takkyun; Park, Kyung-Bae; Heo, Chul-Joon; Satoh, Ryu-Ichi; Yagi, Tadao; Choi, Yeong Suk; Lim, Seon-Jeong; Lee, Sangyoon
• Is Part Of: Journal of materials chemistry. Volume 4:Issue 5(2016)
• Page Start: 1117
• Page End: 1125
• Publication Date: 2016-01-13
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c5tc03567h
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Two novel dipolar donor–acceptor molecules approaching the cyanine limit were used for green-light-selective OPDs. Abstract : We report on two novel p-type small molecules with a donor–acceptor molecular structure for application to green-light-selective organic photodiodes (OPDs). To achieve the requirement of high light selectivity and sensitivity, an electron-donating aryl amino moiety is combined with two respective electron-accepting heterocycles so that the molecules approach cyanine-like character, characterized by intense and sharp absorption. Molecular stacking is controlled by the addition of bulky aryl functional groups to the main backbone to further control the electrical charge transport properties. With this molecular design, a maximum external quantum efficiency close to 61% ( λ max = 550 nm) and a dark-current density below 1.6 nA cm −2 (or specific detectivity D * = 1.19 × 10 13 cm Hz 1/2 W −1 ) at an applied reverse bias of 3 V are obtained when mixed with fullerene (C60 ) in an inverted-structure bulk heterojunction OPD composed of two transparent electrodes. The potential construction of a full-color photodetector or an image sensor is demonstrated by combining the green-light-selective OPD with a silicon photodiode containing solely blue and red color filters in a stacked architecture.