We report the photoluminescence properties of DC sputtered zinc nitride thin films in the temperature range of 3.7–300 K. Zinc nitride samples grown at 150 °C exhibited a narrow photoluminescence band at 1.38 eV and a broad band at 0.90 eV, which were attributed to the recombination of free carriers with a bound state and deep-level defect states, respectively. The high-energy band followed the Varshni equation with temperature and became saturated at high excitation powers. These results indicate that the high-energy band originates from shallow defect states in a narrow bandgap. Furthermore, a red-shift of the observed features with increasing excitation power suggested the presence of inhomogeneities within the samples.

中文翻译：

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在光致发光测量中观察到的氮化锌带隙的温度依赖性

我们报告了直流溅射氮化锌薄膜在 3.7-300 K 温度范围内的光致发光特性。 在 150 °C 下生长的氮化锌样品表现出 1.38 eV 的窄光致发光带和 0.90 eV 的宽带，这归因于自由载流子分别与束缚态和深能级缺陷态的复合。高能带随着温度遵循 Varshni 方程，并在高激发功率下变得饱和。这些结果表明高能带起源于窄带隙中的浅缺陷态。此外，随着激发功率的增加，观察到的特征发生红移表明样品中存在不均匀性。