BX1–BX2 (X1, X2 = P, As, Sb) lateral heterostructure: novel and efficient two-dimensional photovoltaic materials with ultra-high carrier mobilities

Abstract

Identifying lateral heterostructures (LHSs) with suitable two-dimensional (2D) building blocks is still an urgent challenge in materials science and device physics. In this work, we propose a new series of novel LHSs based on the ideal members of 2D group-VA derivatives, namely BX₁–BX₂ (X₁, X₂ = P, As, Sb) with different connecting edges. Through evaluating their stabilities, electronic properties, and optically related electric behaviors by using first principles calculation methods, a battery of novel and excellent properties are demonstrated including large formation energies, moderate direct band gaps, ultrahigh carrier mobilities, and efficient optical absorptions. Moreover, the electronic devices based on these LHSs show good performance for photoelectric conversion in the visible light region, and more appreciable photocurrents, photon responsivities, external quantum efficiencies, energy conversion efficiencies, and fill factors are explored compared with some other reported 2D materials. We believe the new group of stable and novel BX₁–BX₂ LHSs can provide a new strategy for experimental design and application of future photovoltaic conversion devices and excitonic solar cells.