Linkage effects of linear D-π-A-π-D type diketopyrrolopyrrole- triphenylamine based solution-processable organic small molecule photovoltaic materials
Four novel D-π-A-π-D-type small molecules (SMs) were synthesized and their π-linkage effects were investigated. Among them, SM2 with vinylene as the π-linkage exhibited better molecular coplanarity, reaching a relatively higher power conversion efficiency (PCE) of 3.76%. SM3 and SM4 with acetylene and acrylonitrile as π-linkages exhibited relatively higher open-circuit voltages (VOC) of 0.93 V and 0.90 V, respectively, owing to their deep-lying HOMO levels. These results gave an important guide for developing new materials in solution-processed small molecule solar cells.
Ji, Changyan,Yin, Lunxiang,Wang, Lihui,Jia, Tao,Meng, Shixiang,Sun, Yingji,Li, Yanqin
p. 4019 - 4026
(2014/05/20)
D-π-A-π-D type benzothiadiazole-triphenylamine based small molecules containing cyano on the π-bridge for solution-processed organic solar cells with high open-circuit voltage
Two novel D-π-A-π-D structured small molecules composed of benzothiadiazole and triphenylamine were designed and synthesized. BDCTBT with cyano on the π-bridge exhibited a deep HOMO energy level, resulting in an impressive VOC of up to 1.04 V with a PCE of 3.85%, while non-cyano substituted BDETBT yielded a VOC of 0.94 V and a PCE of 1.99%.