Alkoxyphenyl-thiophene, -selenophene and -furan substituted benzodithiophene based 2D pi-conjugated polymers for polymer solar cells and effect of chalcogen on optoelectronic properties

作者：Chakravarthi Nallan; Kranthiraja Kakaraparthi; Gunasekar Kumarasarny; Gal Yeong Soon; Cho Young Rae^*; Jin Sung Ho^*

来源：Synthetic Metals, 2016, 222: 356-363.

DOI：10.1016/j.synthmet.2016.11.018

• Bulk heterojunction
• Polymer solar cells
• Chalcogen
• Impedance spectroscopy
• Open-circuit voltage
• Flat-band potential

In order to analyze the correlation between the optpelectronic properties and chalcogen present in the conjugated side chain of benzodithiophene (BDT) based 2D pi-conjugated polymers, we synthesized a new series of 2D pi-conjugated polymers P1 (S), P2 (Se), and P3 (0), in which alkoxyphenyl-thiophene, alkoxyphenyl-selenophene and alkoxyphenyl-furan substituted BDT as an electron rich donor unit and thieno[3,4-c]pyrrole-4,6-dione as an "electron deficient acceptor unit, respectively. The P1-P3 showed varied optoelectronic properties with respect to the chalcogen present in the conjugated side chains of donor unit. The bulk heterojunction (BHJ) polymer solar cells (PSCs) based on P1-P3 showed maximum power conversion efficiency of 3.37, 3.53 and 1.54%, respectively. In particular, open-circuit voltages (V-OC) of P1-P3 based PSCs were (0.92, 0.96 and 0.80 V) significantly affected upon chalcogen exchange, which was further analyzed by Mott-Schottky analysis and, the obtained flat-band potential values are well matched with the V-OC of P1-P3 based devices.

• 出版日期2016-12