ITO/Si(n)异质结构的侧向光伏效应研究  

The lateral photovoltaic effect in ITO/Si(n) heterojunction

作　　者：刘亚男 王凌云 乔双 王淑芳[1] 傅广生[1] 

机构地区：[1]河北大学物理科学与技术学院,河北省光电信息重点实验室,保定071002

出　　处：《中国科学：物理学、力学、天文学》2017年第12期88-94,共7页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:51372064);河北省青年拔尖人才支持计划;河北省高等学校科学技术研究重点项目(编号:ZD2016036);河北大学杰出青年基金项目资助

摘　　要：本文报道了由磁控溅射技术在n型单晶Si衬底上制备不同厚度ITO异质结构的侧向光伏效应.通过不同波长和不同功率激光照射下侧向光电压的研究发现,ITO/Si(n)异质结构的位置灵敏度随着激光功率和波长增加而增大,该结果归因于光激发电子-空穴对的数量在相同波长下正比于激光功率,并且在相同功率下正比于激光波长;另外,侧向光伏效应强烈依赖于ITO薄膜的厚度,随着薄膜厚度的增加,侧向光电压和非线性度均呈指数下降,这主要是由于ITO薄膜电阻率减小诱导的表面扩散长度增加所致.我们的研究结果表明,通过合理控制ITO薄膜厚度可以得到灵敏度较高且线性度较好的侧向光电压,有望实现ITO/Si(n)异质结构在位置灵敏探测器领域的潜在应用.The ITO/Si heterojunction has been studied as a solar cell longtime ago, but seldom done on the lateral photovoltaic effect （LPE）. In this paper, we reported a new finding of lateral photovoltaic effect （LPE） in the ITO/Si（n） heterojunctions. The ITO films were prepared directly on the n-type single crystal Si substrate with different thicknesses by magnetron reactive sputtering technology. When we measured the lateral photovoltages in the ITO/Si structures as a function of laser position under illumination of different laser powers and different laser wavelengths, it was found that the LPE increased with both laser power and laser wavelength, which can be ascribed to the increased number of electron-hole pairs resulting from the increased laser power for a constant laser wavelength or the increased laser wavelength for a constant laser power. Moreover, the position sensitivity decreased dramatically with increasing the thickness of ITO thin films, but the nonlinearity seems to be improved gradually, both of which can be successfully explained by the increased carrier diffusion length induced by the decreased resistivity of ITO layer. The ITO/Si（n） heterojunction possesses good position sensitivity and suitable nonlinearity simultaneously when the thickness of ITO layer is 15 nm. Our results may provide important insight that one can obtain a suitable LPE in the ITO/Si（n） heterojunction with higher position sensitivity and lower nonlinearity by controlling the thickness of the ITO thin films, and also suggest that the ITO/Si（n） heterojunction is a potential candidate for developing novel and multifunctional optical sensors.

关 键 词：ITO/Si(n) 侧向光伏效应 灵敏度 薄膜厚度 

分 类 号：TB383.2[一般工业技术—材料科学与工程]