TY - JOUR
T1 - Charge Carrier Dynamics in Cs2AgBiBr6 Double Perovskite
AU - Bartesaghi, Davide
AU - Slavney, Adam H.
AU - Gélvez-Rueda, María C.
AU - Connor, Bridget A.
AU - Grozema, Ferdinand C.
AU - Karunadasa, Hemamala I.
AU - Savenije, Tom J.
PY - 2018
Y1 - 2018
N2 - Double perovskites, comprising two different cations, are potential nontoxic alternatives to lead halide perovskites. Here, we characterized thin films and crystals of Cs2AgBiBr6 by time-resolved microwave conductance (TRMC), which probes formation and decay of mobile charges upon pulsed irradiation. Optical excitation of films results in the formation of charges with a yield times mobility product, φΣμ > 1 cm2/Vs. On excitation of millimeter-sized crystals, the TRMC signals show, apart from a fast decay, a long-lived tail. Interestingly, this tail is dominant when exciting close to the bandgap, implying the presence of mobile charges with microsecond lifetimes. From the temperature and intensity dependence of the TRMC signals, we deduce a shallow trap state density of around 1016/cm3 in the bulk of the crystal. Despite this high concentration, trap-assisted recombination of charges in the bulk appears to be slow, which is promising for photovoltaic applications.
AB - Double perovskites, comprising two different cations, are potential nontoxic alternatives to lead halide perovskites. Here, we characterized thin films and crystals of Cs2AgBiBr6 by time-resolved microwave conductance (TRMC), which probes formation and decay of mobile charges upon pulsed irradiation. Optical excitation of films results in the formation of charges with a yield times mobility product, φΣμ > 1 cm2/Vs. On excitation of millimeter-sized crystals, the TRMC signals show, apart from a fast decay, a long-lived tail. Interestingly, this tail is dominant when exciting close to the bandgap, implying the presence of mobile charges with microsecond lifetimes. From the temperature and intensity dependence of the TRMC signals, we deduce a shallow trap state density of around 1016/cm3 in the bulk of the crystal. Despite this high concentration, trap-assisted recombination of charges in the bulk appears to be slow, which is promising for photovoltaic applications.
UR - http://www.scopus.com/inward/record.url?scp=85043685321&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.8b00572
DO - 10.1021/acs.jpcc.8b00572
M3 - Article
AN - SCOPUS:85043685321
SN - 1932-7447
VL - 122
SP - 4809
EP - 4816
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 9
ER -
