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Interface Optimization via Fullerene Blends Enables Open‐Circuit Voltages of 1.35 V in CH 3 NH 3 Pb(I 0.8 Br 0.2 ) 3 Solar Cells
Author(s) -
Liu Zhifa,
Siekmann Johanna,
Klingebiel Benjamin,
Rau Uwe,
Kirchartz Thomas
Publication year - 2021
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.202003386
Subject(s) - materials science , fullerene , perovskite (structure) , open circuit voltage , band gap , energy conversion efficiency , halide , homo/lumo , optoelectronics , voltage , electron , analytical chemistry (journal) , crystallography , inorganic chemistry , molecule , chemistry , physics , organic chemistry , quantum mechanics
Nonradiative recombination processes are the biggest hindrance to approaching the radiative limit of the open‐circuit voltage for wide bandgap perovskite solar cells. In addition to high bulk quality, good interfaces and good energy level alignment for majority carriers at charge transport layer‐absorber interfaces are crucial to minimize nonradiative recombination pathways. By tuning the lowest‐unoccupied molecular‐orbital of electron transport layers via the use of different fullerenes and fullerene blends, open‐circuit voltages exceeding 1.35 V in CH 3 NH 3 Pb(I 0.8 Br 0.2 ) 3 device are demonstrated. Further optimization of mobility in binary fullerenes electron transport layers can boost the power conversion efficiency as high as 18.9%. It is noted in particular that the V oc fill factor product is >1.096 V, which is the highest value reported for halide perovskites with this bandgap.