Akademik Veri Yönetim Sistemi
2 International Conference on Photovoltaic Science and Technologies, Ankara, Türkiye, 30 Kasım - 02 Aralık 2020, ss.79-80
Two new random copolymers, signed as P1 and P2, were designed and synthesized. 5-(2-ethylhexyl)-4Hthieno[
3,4-c]pyrrole-4,6(5H)-dione (TPD) was utilized as electron-accepting moiety whereas selenophene
was utilized as spacer, 4,8-bis[5-(2-ethylhexyl) thiophen-2-yl]-2,6-bis(trimethylstannyl)benzo[1,2-b:4,5-b’]
(BDT(TiC8)), thiophene and alkylthiophene were utilized as donor moieties. Structural analyses of the
polymers were carried out by attenuated total Reflectance-Fourier-transform infrared spectroscopy
(ATR−FTIR). Weight-average and number-average molecular weights (Mw, Mn) of the polymers were
determined via size exclusion chromatography (SEC). Electrochemical and spectroelectrochemical
measurements were performed to investigate optoelectronic properties. The polymers were used as
donor polymers in active layer to fabricate non-fullerene, bulk heterojunction (BHJ) organic solar cells
(OSCs). BHJ solar cells' device structure is ITO/PEDOT: PSS/Active Layer/LiF/Al, where active layer consists
of ITIC as acceptor and thienopyrroledione containing donors. Various optimization studies (solvent
selection, donor: determination of acceptor ratio, active layer’s mass ratio optimizations, determination
of the active layer's thickness, additive selection and thermal annealing) were carried out to obtain the
best performance from the devices. The device based on P1: ITIC (1:1) blend with a thickness of 161 nm
gave the best performance with a power conversion efficiency (PCE) of 7.94 %. The highest PCE obtained
from P2 based organic solar cell is 1.96 %. P2 exhibited low solubility attributed to the lack of alkyl groups
enhancing polymer solubility, electronic properties, and photovoltaic performances. Our study represents
a synthetic approach to exhibit alkyl chains' effect on OSCs' performance based on TPD containing random
polymers and non-fullerene acceptors.