Investigation of Hole Dopability in Oxygen $2p$-Dominated Bands

Abstract

The development of $p$-type oxide semiconductors remains impeded by the inherently low-lying valence-band maximum (VBM) dominated by O-2$p$ states. A prevailing approach to mitigate this limitation is to elevate the VBM by introducing cation states that hybridize with O-2$p$ orbitals or lie energetically above the O-2$p$ level. Nevertheless, the $p$-type oxides reported to date exhibit limited hole mobilities. To expand the search space, it is essential to accurately understand the intrinsic difficulty of introducing holes into O-2$p$-dominated bands. Accordingly, we evaluated 845 oxides to identify those in which holes can be doped into O-2$p$-dominated bands. Our high-throughput screening revealed CaCdO${}_2$ as the only promising exemplar, in which the VBM is slightly hybridized with deep-lying Cd-3$d$ states. Our screening suggests that hole doping into O-2$p$-dominated bands is extremely difficult and thus reinforces the effectiveness of the traditional ``VBM-raising strategy.''

References in corpus (4)

• BoltzTraP. A code for calculating band-structure dependent quantities
• Polaronic hole localization and multiple hole binding of acceptors in oxide wide-gap semiconductors
• Native defects and $p$-type dopability in transparent $\beta$-TeO${}_2$: A first-principles study
• Exploring Intrinsic and Extrinsic $p$-type Dopability of Atomically Thin $\beta$-TeO${}_2$ from First Principles

Cited by in corpus (2)

• Machine Learning Prediction of Charged Defect Formation Energies from Crystal Structures
• Oxygen-deficiency-driven phase segregation enables enhanced hole transport in amorphous tellurium oxides