N掺杂Cu2O宽光谱吸收材料的实验与计算研究

采用热氧化的方法制备了高择优取向的Cu2O薄膜。并通过离子注入对其进行了不同浓度的N掺杂。吸收谱测试显示高剂量的N掺杂Cu2O薄膜在带隙以下有吸收峰出现。采用第一性原理方法对N掺杂Cu2O的几何、电子结构及光学性质进行了比较系统的研究。计算结果表明,高浓度的N掺杂在Cu2O禁带中引入了一个中间带。价带到中间带的电子跃迁与实验观察到的吸收峰相吻合。实验和计算结果显示N掺杂Cu2O材料在制备宽光谱探测器和中间带太阳电池方面有很大潜能。

A combined experimental-computational study on nitrogen doped Cu2O as the wide-spectrum absorption material

Highly-oriented Cu₂O thin films were prepared by low temperature thermal oxidation of evaporated Cu thin films. The films were doped with different doses of nitrogen by ion implantation. An absorption peak appears below the absorption edge in the absorption spectrum of highly nitrogen doped Cu₂O. The effect of nitrogen doping on the crystal structure, electronic structure and optical properties of Cu₂O were investigated systematically by first-principles calculations. The calculation results indicate that an intermediate energy band exists in the forbidden gap of highly nitrogen doped Cu₂O. The electron transition from the valence band to the intermediate band is consistent with the absorption peak by experimental observation. Experimental and computational results indicate that nitrogen doped Cu₂O could be a suitable absorbing material candidate for wide-spectrum detectors or intermediate band solar cells.