Recently, Sinder et al. (2019) have studied the re-oxidation kinetics of chemically reduced, nitrogen-doped TiO₂. Based on results of their ambipolar diffusion analysis, in this Comment, the associated electric field distribution and its evolution are studied. Numerical as well as approximate analytical solutions are given. It is found that the electric field profile exhibits a step-like shape penetrating from the specimen surface up to the ambipolar diffusion front. The ambipolar diffusion front pattern and its formation is discussed with special consideration of the impact of the internal electric field on the fluxes of the charged defects which are composed of counteracting diffusion-induced and field-driven contributions.

最近，Sinder 等人。(2019) 研究了化学还原的氮掺杂 TiO ₂的再氧化动力学。基于他们的双极扩散分析的结果，在这篇评论中，研究了相关的电场分布及其演变。给出了数值和近似解析解。发现电场分布呈现出从样品表面向上穿透到双极扩散前沿的阶梯状形状。讨论了双极扩散前沿图案及其形成，特别考虑了内部电场对带电缺陷通量的影响，这些带电缺陷由抵消扩散引起的和场驱动的贡献组成。