TY - JOUR
T1 - Understanding the Performance-Limiting Factors of Cs2AgBiBr6 Double-Perovskite Solar Cells
AU - Longo, Giulia
AU - Mahesh, Suhas
AU - Buizza, Leonardo R. V.
AU - Wright, Adam D.
AU - Ramadan, Alexandra J.
AU - Abdi-Jalebi, Mojtaba
AU - Nayak, Pabitra K.
AU - Herz, Laura M.
AU - Snaith, Henry J.
N1 - Funding information:
This work was funded by EPSRC through projects EP/M015254/2, EP/S516119/1, EP/M005143/1, and EP/P032591/1 and by H2020 through the European Union’s Horizon 2020 research and innovation programme through PERTPV project under Grant Agreement No. 763977 and CHEOPS project under Grant Agreement No. 730135. S.M. acknowledges funding from the Rhodes Trust (India & Worcester 2016). L.R.V.B. thanks the Centre for Doctoral Training in New and Sustainable Photovoltaics and to the Oxford-Radcliffe Scholarship for financial support. P.K.N. acknowledges the support via intramural funds at TIFR Hyderabad from the Department of Atomic Energy (DAE), India. M.A.-J. thanks Cambridge Materials Limited, Wolfson College, University of Cambridge, and EPSRC for their funding and technical support.
PY - 2020/7/10
Y1 - 2020/7/10
N2 - Double perovskites have recently emerged as possible alternatives to lead-based halide perovskites for photovoltaic applications. In particular, Cs2AgBiBr6 has been the subject of several studies because of its environmental stability, low toxicity, and its promising optoelectronic features. Despite these encouraging features, the performances of solar cells based on this double perovskite are still low, suggesting severe limitations that need to be addressed. In this work we combine experimental and theoretical studies to show that the short electron diffusion length is one of the major causes for the limited performance of Cs2AgBiBr6 solar cells. Using EQE measurements on semitransparent Cs2AgBiBr6 solar cells we estimate the electron diffusion length to be only 30 nm and corroborated this value by terahertz spectroscopy. By using photothermal deflection spectroscopy and surface photovoltage measurements we correlate the limited electron diffusion length with a high density of electron traps. Our findings highlight important faults affecting this double perovskite, showing the challenges to overcome and hinting to a possible path to improve the efficiency of Cs2AgBiBr6 solar cells.
AB - Double perovskites have recently emerged as possible alternatives to lead-based halide perovskites for photovoltaic applications. In particular, Cs2AgBiBr6 has been the subject of several studies because of its environmental stability, low toxicity, and its promising optoelectronic features. Despite these encouraging features, the performances of solar cells based on this double perovskite are still low, suggesting severe limitations that need to be addressed. In this work we combine experimental and theoretical studies to show that the short electron diffusion length is one of the major causes for the limited performance of Cs2AgBiBr6 solar cells. Using EQE measurements on semitransparent Cs2AgBiBr6 solar cells we estimate the electron diffusion length to be only 30 nm and corroborated this value by terahertz spectroscopy. By using photothermal deflection spectroscopy and surface photovoltage measurements we correlate the limited electron diffusion length with a high density of electron traps. Our findings highlight important faults affecting this double perovskite, showing the challenges to overcome and hinting to a possible path to improve the efficiency of Cs2AgBiBr6 solar cells.
UR - http://www.scopus.com/inward/record.url?scp=85089475511&partnerID=8YFLogxK
U2 - 10.1021/acsenergylett.0c01020
DO - 10.1021/acsenergylett.0c01020
M3 - Letter
SN - 2380-8195
VL - 5
SP - 2200
EP - 2207
JO - ACS Energy Letters
JF - ACS Energy Letters
IS - 7
ER -
