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Layer‐by‐Layer Solution‐Processed Low‐Bandgap Polymer‐PC 61 BM Solar Cells with High Efficiency
Author(s) -
Cheng Pei,
Hou Jianhui,
Li Yongfang,
Zhan Xiaowei
Publication year - 2014
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201301349
Subject(s) - materials science , energy conversion efficiency , polymer solar cell , acceptor , active layer , band gap , annealing (glass) , optoelectronics , electron acceptor , layer (electronics) , polymer , doping , chemical engineering , analytical chemistry (journal) , nanotechnology , photochemistry , organic chemistry , composite material , chemistry , physics , engineering , condensed matter physics , thin film transistor
Polymer solar cells (PSCs) are fabricated without solvent additives using a low‐bandgap polymer, PBDTTT‐C‐T, as the donor and [6,6]‐phenyl‐C61‐butyric‐acid‐methyl‐ester (PC 61 BM) as the acceptor. Donor‐acceptor blend and layer‐by‐layer (LL) solution process are used to form active layers. Relative to the blend devices, the LL devices exhibit stronger absorption, better vertical phase separation, higher hole and electron mobilities, and better charge extraction at correct electrodes. As a result, after thermal annealing the LL devices exhibit an average power conversion efficiency (PCE) of 6.86%, which is much higher than that of the blend devices (4.31%). The best PCE of the LL devices is 7.13%, which is the highest reported for LL processed PSCs and among the highest reported for PC 61 BM‐based single‐junction PSCs.