非常规中间带半导体BixSn1-xO2多维复合薄膜量子工程与超灵敏紫外探测器研究

紫外探测器在天文、国防、通信、遥感等领域具有重要应用。本项目拟解决SnO2基紫外探测器低暗电流密度和高响应度难以兼备的本征问题，提高器件对极弱紫外光的感测能力。采用物理气相沉积和干涉光刻技术生长非常规中间带半导体BixSn1-xO2纳米线膜(0.009<x<0.09)。通过量子调控工程，在BixSn1-xO2带隙中形成高态密度和满电子占据的非常规中间带；研究生长工艺参数对纳米线膜的微结构、元素成分和价态、光学和电学性能等影响，建立Bi化合价与纳米线膜物性之间的调控关系。设计构筑光导型紫外探测器，确定响应度，探测率，动态范围等器件性能参数随波长和器件偏压等的变化关系，获得响应度>100A/W，探测率>E17Jones，响应时间<50ms紫外探测器。研究纳米线的径向尺寸对探测器性能的影响规律，建立两者之间的构效关系。通过本项目实施，将为SnO2基超灵敏紫外探测器的发展和应用奠定基础。

The aim of this project is to fabricate intermediate band semiconductor BixSn1-xO2(0.009<x<0.09) multi-dimensional nanowires films by physical vapor deposition and lift off technology; to study the influence of fabrication parameters on the crystal structures, composites, elements chemical states of nanowires films; to establish the relationship between equivalent valence of Bi and optical and electrical properties of BixSn1-xO2 nanowires films; To construct the ultraviolet photoconductors based on BixSn1-xO2 nanowires films. The figure of merits of the UV photodetector, including spectral responsibility, detectivity, dynamic range, will be investigated under different wavelengths and bias voltages. To study the structure-performance relationship between the nanowire diameter and photodetector. To obtain a high performance BixSn1-xO2 film based-UV photodetector with responsibility more than 100 A/W, detectivity higher than 1E17 Jones and the response time less than 50 ms. The UV photodetectors have drawn considerable interests due to their ubiquitous applications in the areas like astronomical telescope, spatial secure optical communication, chemical or biological agent sensing, missile warning. Due to excellent properties, including wide bandgap (3.6 eV), large absorption coefficient (>1E5 /cm) in DUV band, high transparency in visible light range, exotic electrical properties (mobility: 13500 cm2/V•s@45K), and high physicochemical stability, the SnO2 is a promising material to construct UV photodetectors. Up to now, there is still a great challenge to actualize high detectivity photodetectors based on SnO2 through improving the photocurrent gain and decreasing the dark current density. The resolve of above challenge through intermediate band engineering in BixSn1-xO2 semiconductor is significant for both science and technology application, and will provide some basis on the development of SnO2-based UV optoelectronic devices.