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Enhanced Open‐Circuit Voltage in Colloidal Quantum Dot Photovoltaics via Reactivity‐Controlled Solution‐Phase Ligand Exchange
Author(s) -
Jo Jea Woong,
Kim Younghoon,
Choi Jongmin,
Arquer F. Pelayo García,
Walters Grant,
Sun Bin,
Ouellette Olivier,
Kim Junghwan,
Proppe Andrew H.,
QuinteroBermudez Rafael,
Fan James,
Xu Jixian,
Tan Chih Shan,
Voznyy Oleksandr,
Sargent Edward H.
Publication year - 2017
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201703627
Subject(s) - photovoltaics , materials science , dispersity , quantum dot , open circuit voltage , reactivity (psychology) , energy conversion efficiency , nanotechnology , colloid , ligand (biochemistry) , phase (matter) , etching (microfabrication) , chemical engineering , optoelectronics , photovoltaic system , voltage , chemistry , polymer chemistry , organic chemistry , alternative medicine , ecology , receptor , pathology , engineering , biology , biochemistry , layer (electronics) , quantum mechanics , medicine , physics
The energy disorder that arises from colloidal quantum dot (CQD) polydispersity limits the open‐circuit voltage ( V OC ) and efficiency of CQD photovoltaics. This energy broadening is significantly deteriorated today during CQD ligand exchange and film assembly. Here, a new solution‐phase ligand exchange that, via judicious incorporation of reactivity‐engineered additives, provides improved monodispersity in final CQD films is reported. It has been found that increasing the concentration of the less reactive species prevents CQD fusion and etching. As a result, CQD solar cells with a V OC of 0.7 V (vs 0.61 V for the control) for CQD films with exciton peak at 1.28 eV and a power conversion efficiency of 10.9% (vs 10.1% for the control) is achieved.