Abstract Highly ordered, anodically grown TiO2 nanotubes on titanium supports were annealed in ammonia atmosphere in order to incorporate nitrogen doping (≤2 at.%) in the titanium oxide lattice. FESEM micrographs revealed nanotubes with an average outer diameter of 101.5 ± 1.5 nm and an average wall thickness of about 13 nm. Anatase crystals were formed inside the tubes after annealing in ammonia atmosphere for 30 min. With further annealing, rutile peaks appeared due to the thermal oxidation of the foil and rise as the duration of heat treatment was increased. The concentration and chemical nature of nitrogen in the nanotube arrays can be correlated to the optical response of dry-pressed heterojunctions of doped TiO2/CH3NH3PbI3 single crystals. The N-TiO2/perovskite heterojunction with the highest amount of interstitial nitrogen exhibited an improved photocurrent, indicating the importance of the semiconductor doping-based heterojunction optimization strategies to deliver competitive levels of halide perovskite-based optoelectronic devices to be envisioned for urban infrastructures.

中文翻译：

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干压阳极氧化二氧化钛纳米管/CH3NH3PbI3单晶异质结：N掺杂的有益作用

摘要 为了在氧化钛晶格中掺入氮掺杂（≤ 2 at.%），钛载体上高度有序、阳极生长的 TiO2 纳米管在氨气中退火。FESEM 显微照片显示纳米管的平均外径为 101.5 ± 1.5 nm，平均壁厚约为 13 nm。在氨气氛中退火 30 分钟后，在管内形成锐钛矿晶体。随着进一步退火，由于箔的热氧化而出现金红石峰，并且随着热处理时间的增加而升高。纳米管阵列中氮的浓度和化学性质可能与掺杂 TiO2/CH3NH3PbI3 单晶的干压异质结的光学响应相关。