We report the band structure of Ba-deficient BaTiO₃ as a p-type semiconductor, studied by a combination of light reflectance and photoelectron yield spectroscopy. Two acceptor levels were observed at the tail of a valence band. As the quantity of Ba vacancies increased, the density of state of the two acceptor levels also increased. The levels of the conduction band minimum and the valence band maximum shifted far away from the vacuum level, but the bandgap seems to be independent of Ba deficient concentration. For classical semiconductors such as Si and GaAs, the observation of impurity levels is restricted to low temperatures (∼20 K) owing to their narrow bandgaps. Oxide semiconductors have now been demonstrated with wide bandgaps and acceptor levels, at normal operating temperatures, which could lead to new device designs in the future.

中文翻译：

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光反射率和光电子产率谱能够实现p型Ba1-xTiO3半导体中受体水平的测量

我们报告了Ba不足的BaTiO ₃的能带结构作为一种p型半导体，通过光反射率和光电子产率光谱学的结合进行了研究。在价带的尾部观察到两个受体水平。随着Ba空位数量的增加，两个受体水平的状态密度也增加了。导带最小值和价带最大值的水平远离真空水平，但带隙似乎与钡缺乏浓度无关。对于诸如Si和GaAs之类的经典半导体，由于其窄带隙，杂质水平的观察仅限于低温（〜20 K）。现在已经证明，在正常工作温度下，氧化物半导体具有较宽的带隙和受主能级，这可能会导致未来的新器件设计。