# Orbital-resolved tuning of electronic thermal conductivity in monolayer h-B2O via doping in the diffusive regime

## TL;DR

This paper studies how doping affects the thermal conductivity of a 2D material called h-B2O, showing that it can be tuned in a direction-dependent way.

## Contribution

The first calculation of electronic thermal conductivity in h-B2O using the Kubo-Greenwood formalism, revealing orbital-resolved and anisotropic behavior.

## Key findings

- h-B2O shows strong anisotropy in electronic thermal conductivity with higher values along the zigzag direction.
- n-type doping enhances ETC via the Pz orbital, while p-type doping causes only minor changes.
- Orbital symmetry and spatial orientation significantly influence thermal transport in h-B2O.

## Abstract

The highly stable two-dimensional monolayer honeycomb borophene oxide (h-B2O) has attracted considerable interest due to its unique topological features and potential superconducting behavior. In this study, a tight-binding Hamiltonian is constructed by incorporating the Py and Pz orbitals of boron, effectively capturing the essential physics governing the material’s low-energy electronic behavior. Additionally, for the first time, the electronic thermal conductivity (ETC) of monolayer h-B2O is calculated using the Kubo-Greenwood formalism within the diffusive transport regime. The results reveal strong anisotropy (\documentclass[12pt]{minimal}
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\begin{document}$$\:({\kappa\:}_{xy}$$\end{document}) directions, respectively. Furthermore, we systematically investigate the impact of impurity-induced disorder on ETC in h-B2O under both n-type and p-type doping, employing the T-matrix approximation. In the n-type regime, increasing impurity concentration \documentclass[12pt]{minimal}
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\begin{document}$$\:{n}_{i}$$\end{document} = 2%, 4%, 6% leads to a significant enhancement of the ETC associated with the out-of-plane Pz orbital, attributed to its favorable spatial orientation and higher carrier occupancy. Conversely, the in-plane Py orbital exhibits a reduction in ETC due to increased localization and enhanced electron-electron scattering. Despite this orbital contrast, the total ETC rises along all crystallographic directions, governed by the dominant contribution of the Pz orbital, thereby revealing strong orbital-resolved behavior and pronounced directional anisotropy. In contrast, p-type doping induces only modest changes: the ETC contribution from the Py orbital slightly increases, while that of the Pz orbital is marginally reduced, resulting in an overall weak response of the total ETC. These findings highlight the crucial role of orbital symmetry, spatial orientation, and dopant type in shaping the anisotropic and tunable thermal transport properties of h-B2O. The thermal resilience under p-type doping, alongside the direction-dependent enhancement under n-type doping, positions h-B2O as a promising candidate for nanoscale thermoelectric and thermal management technologies.