Theoretical investigation of charge transfer between two defects in a wide band gap semiconductor

Charge traps in the semiconductor bulk (bulk charge traps) make it difficult to predict the electric field within wide band gap semiconductors. The issue is the daunting number of bulk charge-trap candidates which means the treatment of bulk charge traps is generally qualitative or uses generalized models that do not consider the trap's particular electronic structure. The electric field within a wide band gap semiconductor is nonetheless a crucial quantity in determining the operation of semiconductor devices and the performance of solid-state single-photon emitters embedded within the semiconductor devices. In this work we accurately compute the average electric field measured at the location of NV- charged defects for the substitutional N (NC) concentration of nNC≈1.41×1018cm-3 for the commonly used oxygen-terminated diamond [see D. A. Broadway, Nature Electron. 1, 502 (2018)2520-113110.1038/s41928-018-0130-0]. We achieve this result by evaluating the leading-order contribution to the electric field far away from the surface, which comes from the NC defects that induce the ionization of the NV-. Our results use density-functional theory (DFT) and the principle of band bending. Our work has the potential to aid both in the prediction of the functioning of semiconductor devices and in the prediction and correction of the spectral diffusion that often plagues the optical frequencies of solid-state single-photon emitters upon repeated photoexcitation measurements. Our results for the timescales involved in thermally driven charge transfer also have the potential to aid in investigations of charge dynamics.