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Suppression of Hysteresis Effects in Organohalide Perovskite Solar Cells
Author(s) -
Hou Yi,
Scheiner Simon,
Tang Xiaofeng,
Gasparini Nicola,
Richter Moses,
Li Ning,
Schweizer Peter,
Chen Shi,
Chen Haiwei,
Quiroz Cesar Omar Ramirez,
Du Xiaoyan,
Matt Gebhard J.,
Osvet Andres,
Spiecker Erdmann,
Fink Rainer H.,
Hirsch Andreas,
Halik Marcus,
Brabec Christoph J.
Publication year - 2017
Publication title -
advanced materials interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.671
H-Index - 65
ISSN - 2196-7350
DOI - 10.1002/admi.201700007
Subject(s) - materials science , photocurrent , perovskite (structure) , hysteresis , indium tin oxide , optoelectronics , ionic bonding , monolayer , perovskite solar cell , solar cell , energy conversion efficiency , semiconductor , tin oxide , electrode , chemical physics , nanotechnology , ion , chemical engineering , thin film , doping , condensed matter physics , chemistry , physics , quantum mechanics , engineering
Thin‐film solar cell based on hybrid perovskites shows excellent light‐to‐power conversion efficiencies exceeding 22%. However, the mixed ionic‐electronic semiconductor hybrid perovskite exhibits many unusual properties such as slow photocurrent instabilities, hysteresis behavior, and low‐frequency giant capacitance, which still question us so far. This study presents a direct surface functionalization of transparent conductive oxide electrode with an ultrathin ≈2 nm thick phosphonic acid based mixed C60/organic self‐assembled monolayer (SAM) that significantly reduces hysteresis. Moreover, due to the strong phosphonates bonds with indium tin oxide (ITO) substrates, the SAM/ITO substrates also exhibit an excellent recyclability merit from the perspective of cost effectiveness. Impedance studies find the fingerprint of an ion‐based diffusion process in the millisecond to second regime for TiO 2 ‐based devices, which, however, is not observed for SAM‐based devices at these low frequencies. It is experimentally demonstrated that ion migration can be considerably suppressed by carefully engineering SAM interfaces, which allows effectively suppressing hysteresis and unstable diode behavior in the frequency regime between ≈1 and 100 Hz. It is suggested that a reduced density of ionic defects in combination with the absence of charge carrier accumulation at the interface is the main physical origin for the reduced hysteresis.