TY - JOUR
T1 - Combining Organic Cations of Different Sizes Grants Improved Control over Perovskitoid Dimensionality and Bandgap
AU - Gilley, Isaiah W.
AU - Kwon, Hyoung Woo
AU - Liu, Cheng
AU - Yang, Yi
AU - Huang, Chuying
AU - Wan, Haoyue
AU - Bati, Abdulaziz S.R.
AU - Oriel, Evan H.
AU - Kepenekian, Mikaël
AU - Vishal, Badri
AU - Zeiske, Stefan
AU - Bayikadi, Khasim Saheb
AU - Wiggins, Taylor E.
AU - Vasileiadou, Eugenia S.
AU - Chen, Bin
AU - Schaller, Richard D.
AU - Even, Jacky
AU - De Wolf, Stefaan
AU - Sargent, Edward H.
AU - Kanatzidis, Mercouri G.
N1 - Publisher Copyright:
© 2025 American Chemical Society.
PY - 2025/3/5
Y1 - 2025/3/5
N2 - Because mixed-halide wide-bandgap (1.6-2.0 eV) perovskite solar cells suffer from operating instability related to light-induced halide segregation, it is of interest to study alternative means of bandgap widening. Perovskitoids combine wide bandgaps and structural stability resulting from face- or edge-sharing octahedral connections in their crystal structures. Unfortunately, there existed no prior reports of three-dimensional (3D) perovskitoids having direct bandgaps with optical absorption edges less than 2.2 eV. As the most significant predictor of perovskitoid bandgaps is the fraction of corner-sharing in their crystal structures, we hypothesized that increasing the amount of corner-sharing would access lower bandgaps than previously reported. We accomplished this by mixing a spacer cation within the size range for 3D perovskitoid formation with a smaller perovskite-forming cation. We explored three spacer cations of different sizes: ethylammonium (EA), cyclopropylammonium (c-C3A), and cyclobutylammonium (c-C4A), combining these with methylammonium (MA), and found that the middle cation, c-C3A, pairs with MA to form a 3D perovskitoid with the formula (c-C3A)3(MA)3Pb5I16 and a direct bandgap with an optical absorption edge at 2.0 eV. Solution-processed films of this perovskitoid showed improved light stability over mixed-halide perovskites, and solar cells based on these films exhibit increased maximum power point operating stability compared to reference mixed-halide devices.
AB - Because mixed-halide wide-bandgap (1.6-2.0 eV) perovskite solar cells suffer from operating instability related to light-induced halide segregation, it is of interest to study alternative means of bandgap widening. Perovskitoids combine wide bandgaps and structural stability resulting from face- or edge-sharing octahedral connections in their crystal structures. Unfortunately, there existed no prior reports of three-dimensional (3D) perovskitoids having direct bandgaps with optical absorption edges less than 2.2 eV. As the most significant predictor of perovskitoid bandgaps is the fraction of corner-sharing in their crystal structures, we hypothesized that increasing the amount of corner-sharing would access lower bandgaps than previously reported. We accomplished this by mixing a spacer cation within the size range for 3D perovskitoid formation with a smaller perovskite-forming cation. We explored three spacer cations of different sizes: ethylammonium (EA), cyclopropylammonium (c-C3A), and cyclobutylammonium (c-C4A), combining these with methylammonium (MA), and found that the middle cation, c-C3A, pairs with MA to form a 3D perovskitoid with the formula (c-C3A)3(MA)3Pb5I16 and a direct bandgap with an optical absorption edge at 2.0 eV. Solution-processed films of this perovskitoid showed improved light stability over mixed-halide perovskites, and solar cells based on these films exhibit increased maximum power point operating stability compared to reference mixed-halide devices.
UR - http://www.scopus.com/inward/record.url?scp=85219035150&partnerID=8YFLogxK
U2 - 10.1021/jacs.4c17654
DO - 10.1021/jacs.4c17654
M3 - Article
C2 - 39988940
AN - SCOPUS:85219035150
SN - 0002-7863
VL - 147
SP - 7777
EP - 7787
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 9
ER -