Unraveling the Native Conduction of Trichalcogenides and Its Ideal Band Alignment for New Photovoltaic Interfaces

Abstract

The trichalcogenides Sb 2 S 3 , Sb 2 Se 3 , Bi 2 S 3 , and Bi 2 Se 3 share an orthorhombic crystal structure and have recently been pointed out as promising materials for application in solar energy harvesting, such as photovoltaic solar cells, because of their ultimate structural and electronic/optical properties. In this work, using a firstprinciples theoretical approach, we investigated the origin of the electrical conduction in bulk systems as well as the energy band alignment in different heterostructures composed of these compounds. In the first part, formation energy and thermodynamic transition energy of native point defects are evaluated. In the second part, surface properties such as free energy and electron affinity were obtained. In the third part, the energy alignments of some possible heterostructures were proposed. The excellent agreement between theoretical results and reported experimental values indicates that these trichalcogenides have their electrical properties ruled by native point defects, mainly antisites. The energy alignment between the trichalcogenides and usual photovoltaic substrates shows that these materials can be successfully applied to the construction of type-II staggered heterojunctions. A last analysis is done by considering only homo-and heterojunction of trichalcogenides, showing that these materials could lead to high-efficiency cells with broad spectral absorption and high conduction/valence band offsets.

Vapor transport deposition of antimony selenide thin film solar cells with 7.6% efficiency

“…Therefore, we tentatively attributed H1 and H2 defects to V Sb and Se Sb defects, respectively. As reported by Tumelero et al 44 , the antisite defects dominated the distribution of defects in trichalcogenides due to the similar sizes of the constituent atoms. Our previous simulation also showed that Se Sb and antimony antisite (Sb Se ) are acceptor and donor defects, respectively 11 .…”

First-principles calculation of intrinsic defect chemistry and self-doping in PbTe

“…1, the literature in thermoelectric materials often shows qualitatively different results. [14][15][16][17][18] Here, we consider PbTe a well studied material with strong spin-orbit coupling, to demonstrate the challenges posed in first-principles based density functional theory (DFT) calculations aimed at bulk properties, [19][20][21][22][23][24][25] and intrinsic defects. 14,15,[26][27][28] The DFT calculations employing the local density approximation (LDA) 29 or the generalized gradient approximation (GGA) 30 for exchange correlation provide only a qualitative description of the electronic structure of PbTe.…”

Review of Recent Progress in Antimony Chalcogenide‐Based Solar Cells: Materials and Devices

“…The mobility of Sb 2 Se 3 along the [0 0 1] direction can be as high as 20 cm 2 V −1 s −1 , and the electron diffusion length along the [0 0 1] direction under high illumination is 1.7 µm . First‐principles theoretical calculations demonstrated that the electrical properties of antimony chalcogenides were ruled by native point defects (mainly antisites) and that these materials could lead to high‐efficiency solar cells because of their ultimate structural and electronic/optical properties . Typical properties of antimony chalcogenides are summarized in Table .…”