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Updated: Jan 24, 2026

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
Band Alignment Boosts Charge-Carrier Collection in Sn-based Perovskite over Pb Counterparts
Binghan Li1,2,3, Ruiying Long1,2,3, Qishun Yao1
1School of Physical Science and Technology , ShanghaiTech University , Shanghai 201210 , China.
Abstract:
The diverse elemental compositions endow metal halide perovskites with tailorable electronic structures and broad optoelectronic applications. For Sn-based perovskites, their bandedge positions, which govern interfacial charge-carrier transport, are less well studied than their Pb counterparts. In this work, the valence band maximum (VBM) of CsSnBr3 was experimentally and theoretically determined to be -5.2 eV, to which Au forms a good contact. The conduction band minimum (CBM) of CsSnBr3 at -3.4 eV is matched by 1,3,5-tris(4-phenylquinolin-2-yl)benzene (TQB), an organic electron transport material and a ligand to Sn(II). Thanks to proper band alignment, the device structure Al/TQB/CsSnBr3/Au constitutes a photodetector responsive to the entire visible spectrum without a bias voltage and outperforms Pb-based devices under similar conditions. Our results highlight the advantage of combined experimental and theoretical tools in understanding intrinsic material properties and guiding device fabrication.
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