10.1021/acsenergylett.7b00525.s001
Ian L. Braly
Ian L.
Braly
Ryan J. Stoddard
Ryan J.
Stoddard
Adharsh Rajagopal
Adharsh
Rajagopal
Alexander R. Uhl
Alexander R.
Uhl
John K. Katahara
John K.
Katahara
Alex K.-Y. Jen
Alex K.-Y.
Jen
Hugh W. Hillhouse
Hugh W.
Hillhouse
Current-Induced Phase Segregation in Mixed Halide
Hybrid Perovskites and its Impact on Two-Terminal Tandem Solar Cell
Design
American Chemical Society
2017
incident light filter
Current-Induced Phase Segregation
phase segregation
valence band holes
FA
MAC
Mixed Halide Hybrid Perovskites
4 sun injection
MA
Br
halide perovskites phase
conduction band electrons
FAC
1 sun equivalent
CIGS bottom cell
Two-Terminal Tandem Solar Cell Design Mixed halide
2017-07-24 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Current-Induced_Phase_Segregation_in_Mixed_Halide_Hybrid_Perovskites_and_its_Impact_on_Two-Terminal_Tandem_Solar_Cell_Design/5248336
Mixed
halide hybrid perovskites are of significant interest because
their bandgap can be tuned as a current-matched top-cell in tandem
photovoltaics. However, several mixed halide perovskites phase segregate
under illumination, exhibit large voltage deficits, and produce unstable
photocurrents. We investigate the origin of phase segregation and
implication for tandems with mixed halide large-bandgap (∼1.75
eV) perovskites. We show explicitly that MAPb(I<sub>0.6</sub>Br<sub>0.4</sub>)<sub>3</sub> and (MA<sub>0.9</sub>,Cs<sub>0.1</sub>)Pb(I<sub>0.6</sub>,Br<sub>0.4</sub>)<sub>3</sub>, termed “MA”
and “MACs”, respectively, rapidly phase segregate in
the dark upon 1 sun equivalent current injection. This is direct experimental
evidence that conduction band electrons or valence band holes are
the culprit behind phase segregation. In contrast, (FA<sub>0.83</sub>,Cs<sub>0.17</sub>)Pb(I<sub>0.66</sub>,Br<sub>0.34</sub>)<sub>3</sub>, or “FACs,” prepared at only 75 °C resists phase
segregation below 4 sun injection. FACs prepared at 165 °C yields
larger grains and withstands higher injected carrier concentrations
before phase segregation. The FACs and MACs devices sustain near constant
power output at 1 sun and do not affect the current output of a CIGS
bottom cell when used as an incident light filter.