Orbital-Resolved Tuning of Electronic Thermal Conductivity in Monolayer h-B2O via Doping in the Diffusive Regime

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 materials 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 (κyy ≫ κxx), with room-temperature ETC values of 5.9 × 10-2 mW.m-1 .K-1 , 1 mW.m-1 .K-1 , and 0.17 mW.m-1 .K-1 along the armchair (κxx), zigzag (κyy), and anomalous Righi-Leduc effect (κxy) 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 (ni = 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.