Authors: Jing Ji Shengjuan Ma Fei Shan Feng Wang Ye Song
Publish Date: 2016/05/12
Volume: 51, Issue: 16, Pages: 7395-7406
Abstract
The present study demonstrates the effect on photovoltaic performance of regioregular poly 3hexylthiophenerrP3HT grafted oxide graphene GO on in situ doping of cadmium sulfide CdS quantum dots QDs GOrrP3HTCdS Firstly CH2OHterminated rrP3HT of different molecular weights MW and distributions synthesized by Grignard metathesis GRIM method was grafted onto carboxylic groups of GO via esterification reaction Then the GOrrP3HTCdS was prepared with an oleylamine solution composed of 1 mmol of cadmium and 1 mmol high pure sulfur in the presence of GOrrP3HT The covalent linkage and the strong electronic interaction between the rrP3HT and graphene moieties in GOrrP3HT were confirmed by spectroscopic analyses XPS and FTIR The photovoltaic properties of as prepared nanocomposites are evaluated by UV–Vis spectroscopy photoluminescence and electrochemical measurements and are found to be strongly affected by MW which influences the behavior of the bulk heterojunction organic solar cells based on this material It is found that the optical and electrochemical properties of the resultant GOrrP3HTCdS nanocomposite are relatively better than that of conventional composite in which the pristine graphene CdS and rrP3HT or GOrrP3HT are physically mixed together The significant PL quenching is attributed to additional decaying paths of the excited electrons through the CdS Bulk heterojunction photovoltaic devices with a thin film of GOrrP3HTCdS containing higher molecular weights of rrP3HT show an increase in the power conversion efficiency by about three times with respect to their counterparts based on GOrrP3HT/CdS and GO/rrP3HT/CdS due to improvement in contact between GOrrP3HT and CdS and enhancement in the device parameters like fill factor and opencircuit voltage V OC
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