Kim, Jung Kyu Park, Myung Jin Kim, Sang Jin Wang, Dong Hwan Cho, Sung Pyo Bae, Sukang Park, Jong Hyeok Hong, Byung Hee 2024-01-20T12:01:03Z 2024-01-20T12:01:03Z 2021-09-05 2013-08 1936-0851 https://pubs.kist.re.kr/handle/201004/127827 Graphene quantum dots (GQDs) have been considered as a novel material because their electronic and optoelectronic properties can be tuned by controlling the size and the functional groups of GQDs. Here we report the synthesis of reduction-controlled GQDs and their application to bulk heterojunction (BHJ) solar cells with enhanced power conversion, efficiency (PCE). Three different types of GQDs-graphene oxide quantum dots (GOQDs), 5 h reduced GQDs, and 10 h reduced GQDs-were tested in BM solar cells, and the results indicate that GQDs play an important role in increasing optical absorptivity and charge carrier extraction of the BIB solar cells. The enhanced optical absorptivity by rich functional groups in GOQDs increases short-circuit current, while the improved conductivity of reduced GQDs leads to the increase of fill factors. Thus, the reduction level of GQDs needs to be intermediate to balance the absorptivity and conductivity. Indeed, the partially reduced GQDs yielded the outstandingly improved PCE of 7.60% in BM devices compared to a reference device without GQDs (6.70%). English AMER CHEMICAL SOC ELECTRON-TRANSPORT LAYER PHOTOVOLTAIC DEVICES HIGH-PERFORMANCE OXIDE-FILMS AG NANOPARTICLES EMITTING-DIODES POLYMER TRANSPARENT ENHANCEMENT REDUCTION Balancing Light Absorptivity and Carrier Conductivity of Graphene Quantum Dots for High-Efficiency Bulk Heterojunction Solar Cells Article 10.1021/nn402606v 1 ACS NANO, v.7, no.8, pp.7207 - 7212 ACS NANO 7 8 7207 7212 scie scopus 000323810600085 2-s2.0-84883259391 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Chemistry Science & Technology - Other Topics Materials Science Article ELECTRON-TRANSPORT LAYER PHOTOVOLTAIC DEVICES HIGH-PERFORMANCE OXIDE-FILMS AG NANOPARTICLES EMITTING-DIODES POLYMER TRANSPARENT ENHANCEMENT REDUCTION graphene quantum dots bulk heterojunction solar cells light absorption conductivity