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Updated: Nov 12, 2025

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
Engineering bandgap of CsPbI3 over 1.7 eV with enhanced stability and transport properties
Shumao Xu1,2, Alberto Libanori1, Gan Luo2
1Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Abstract:
Potential multijunction application of CsPbI3 perovskite with silicon solar cells to reach efficiencies beyond the Shockley-Queisser limit motivates tremendous efforts to improve its phase stability and further enlarge its band gap between 1.7 and 1.8 eV. Current strategies to increase band gap via conventional mixed halide engineering are accompanied by detrimental phase segregation under illumination. Here, ethylammonium (EA) in a relatively small fraction (x < 0.15) is first investigated to fit into three-dimensional CsPbI3 framework to form pure-phase hybrid perovskites with enlarged band gap over 1.7 eV. The increase of band gap is closely associated with the distortion of Pb-I octahedra and the variation of the average Pb-I-Pb angle. Meanwhile, the introduction of EA can retard the crystallization of perovskite and tune the perovskite structure with enhanced phase stability and transport properties.
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