n-Si/p-CuI异质结的制备及其光电特性研究

Fabrication and Characterization of p-CuI/n-Si Heterojunction Diodes

摘要:

采用成本低廉的连续离子层沉积法通过在n型Si衬底上沉积γ相的多晶结构的CuI薄膜而制备了CuI/n-Si异质结。并通过测试其光照下的I-V、C-V特性对其光电特性、载流子输运特性及导电机理进行了研究。研究表明CuI/n-Si异质结存在良好的整流特性，由于在CuI/n-Si异质结界面处的导带补偿与价带补偿相差较大，在正向电压、无光照下，导电机理为空间电荷限制电流导电，此时空穴电流主导; 在光照下，异质结表现出良好的光电响应，因此可以广泛应用在光电探测和太阳电池等领域。

Abstract:

Polycrystalline γ-CuI films were deposited on n-Si substrate with the method of low-cost successive ionic layer adsorption. Then p-CuI/n-Si heterojunction diodes were prepared with the prepared films. The optical-electrical characteristics, carrier transportation properties and conductive mechanism were studied based on analyzing its I-V and C-V characteristics under illumination. It is shown that the p-CuI/n-Si heterojunction shows good rectification characteristic. As the big difference between conduction band offset and the valence band offset at the interface of heterojunction, the conductive mechanism is the space-charge limited current (SCLC) conduction at forward bias voltage with no illumination, and it is dominated by the hole current. While under illumination, the heterojunction diodes show good photoelectric response, which makes it suitable for photodetection, photovoltaic devices and other fields.