p-CuSCN/n-Si异质结的光电特性研究

Study on Photoelectron Characterization of p-CuSCN/n-Si Heterojunction

采用成本廉价的连续离子层沉积法在n型Si衬底上沉积β相的六方晶体结构的CuSCN薄膜制备了p-CuSCN/n-Si异质结。并通过测试其光照下的I-V和C-V特性对其光电特性以及载流子输运特性与导电机理进行了研究。研究表明,CuSCN/n-Si异质结存在良好的整流特性;由于在p-CuSCN/n-Si异质结界面处的导带补偿与价带补偿相差较大的缘故,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。

p-CuSCN /n-Si heterojunction was fabricated at a low cost by depositing p-CuSCN films using successive ionic layer adsorption and reaction（SILAR） on n-Si substrates.The structure of p-CuSCN films analyzed by X-ray diffraction spectroscopy was β-phase structure.The photoelectric characteristics,carrier transport properties and conduction mechanisms of p-CuSCN/ n-Si were studied based on the testing of current-voltage（I-V） and capacitance-voltage（C-V） characteristics.The result shows that CuSCN / n-Si heterostructure junction has a good rectifying characteristic.Because the conduction band offset of the p-CuSCN/n-Si heterojunction is larger than the valence band offset,the current transport mechanism is dominated by the space-charge limited current（SCLC） conduction at forward bias voltages with no illumination.In this voltages area,a single carrier injection was induced and the main current of p-CuSCN/n-Si heterojunction was hole current.With illumination the CuSCN/n-Si heterojunction exhibits its good photoelectric response charactristic.This heterojunction diode can be well used for photoelectric detections and solar cells.