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Updated: Jan 16, 2026

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
In-plane anisotropy-driven directional charge transport in van der Waals p-n heterojunctions
Rahul Paramanik1, Tanima Kundu1, Soumik Das1
1School of Physical Sciences, Indian Association for the Cultivation of Science, 2A & B Raja S. C. Mullick Road, Jadavpur, Kolkata-700032, India. sspsdd@iacs.res.in.
Abstract:
Low-symmetry two-dimensional (2D) van der Waals (vdW) materials enable anisotropic charge transport, crucial for polarization-sensitive optoelectronics. In this study, a p-GeS/n-MoS2 heterostructure diode is investigated, where the anisotropic band dispersion of GeS, revealed by angle-resolved photoemission spectroscopy (ARPES), governs directional charge flow. Angle-resolved Raman spectroscopy confirms the crystallographic orientation, and transport measurements in GeS field-effect transistors (FETs) show a mobility anisotropy of ∼3.4. The heterojunction exhibits orientation-dependent diode characteristics, anti-ambipolar transport, and a type-II band alignment, leading to anisotropic optoelectronic response. These findings establish a pathway for utilizing electronic anisotropy in vdW heterostructures for energy-efficient rectification.
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