TY - JOUR
T1 - Sequential Formation of Tunable-Bandgap Mixed-Halide Lead-Based Perovskites
T2 - In Situ Investigation and Photovoltaic Devices
AU - Barrit, Dounya
AU - Zhang, Yalan
AU - Yang, Tinghuan
AU - Tang, Ming Chun
AU - Li, Ruipeng
AU - Smilgies, Detlef M.
AU - Liu, Shengzhong
AU - Anthopoulos, Thomas D.
AU - Amassian, Aram
AU - Zhao, Kui
N1 - Publisher Copyright:
© 2020 Wiley-VCH GmbH
PY - 2021/1
Y1 - 2021/1
N2 - Inorganic−organic hybrid perovskites MAPb(IxBr1−x)3 (0 < x < 1) hold promise for efficient multi-junction or tandem solar cells due to tunable bandgap and improved long-term stability. However, the phase transformation from Pb(IxBr1−x)2 precursors to perovskites is not fully understood which hinders further improvement of optoelectronic properties and device performance. Here, adaptation of the two-step deposition method, which enables the direct probe into the growth dynamics of perovskites using in situ diagnostics, and a detailed view of the effects of solvent, lead halide film solvation, and Br incorporation and alloying on the transformation behavior is presented. The in situ measurements indicate a strong tendency of lead halide solvation prior to crystallization during solution-casting Pb(IxBr1−x)2 precursor from a dimethyl sulfoxide (DMSO) solvent. Highly-efficient intramolecular exchange is observed between DMSO molecules and organic cations, leading to room-temperature conversion of perovskite and high-quality films with tunable bandgap and superior optoelectronic properties in contrast to that obtained from crystalline Pb(IxBr1−x)2. The improved properties translate to easily tunable and a relatively higher power conversion efficiency of 16.42% based on the mixed-halide perovskite MAPb(I0.9Br0.1)3. These findings highlight the benefits that solvation of the precursor phases, together with bromide incorporation, can have on the microstructure, morphology, and optoelectronic properties of these films.
AB - Inorganic−organic hybrid perovskites MAPb(IxBr1−x)3 (0 < x < 1) hold promise for efficient multi-junction or tandem solar cells due to tunable bandgap and improved long-term stability. However, the phase transformation from Pb(IxBr1−x)2 precursors to perovskites is not fully understood which hinders further improvement of optoelectronic properties and device performance. Here, adaptation of the two-step deposition method, which enables the direct probe into the growth dynamics of perovskites using in situ diagnostics, and a detailed view of the effects of solvent, lead halide film solvation, and Br incorporation and alloying on the transformation behavior is presented. The in situ measurements indicate a strong tendency of lead halide solvation prior to crystallization during solution-casting Pb(IxBr1−x)2 precursor from a dimethyl sulfoxide (DMSO) solvent. Highly-efficient intramolecular exchange is observed between DMSO molecules and organic cations, leading to room-temperature conversion of perovskite and high-quality films with tunable bandgap and superior optoelectronic properties in contrast to that obtained from crystalline Pb(IxBr1−x)2. The improved properties translate to easily tunable and a relatively higher power conversion efficiency of 16.42% based on the mixed-halide perovskite MAPb(I0.9Br0.1)3. These findings highlight the benefits that solvation of the precursor phases, together with bromide incorporation, can have on the microstructure, morphology, and optoelectronic properties of these films.
KW - high performances
KW - hybrid perovskite solar cells
KW - in situ grazing incidence wide-angle X-ray scattering
KW - mixed halides
KW - solution processing
KW - two-step conversion
UR - http://www.scopus.com/inward/record.url?scp=85096713551&partnerID=8YFLogxK
U2 - 10.1002/solr.202000668
DO - 10.1002/solr.202000668
M3 - Article
AN - SCOPUS:85096713551
SN - 2367-198X
VL - 5
JO - Solar RRL
JF - Solar RRL
IS - 1
M1 - 2000668
ER -
