摘要
以p Si(111)为衬底,用水热法首次制得六棱微管ZnO。并以此为有源区利用平面磁控溅射技术沉积得到Ag叉指状电极,从而制作了Ag/n ZnO肖特基势垒结紫外探测器。对该紫外光探测器的暗电流和 365nm波长光照下的光电流、光响应和量子效率进行了测试。测试结果表明:Ag和ZnO六棱管间已形成肖特基接触,其有效势垒高度为 0. 35eV。无光照时,暗电流很小,当用λ=365nm的光照射Ag/n ZnO肖特基结时,在 5, 9V偏压时,光生电流分别为 25. 6, 57. 9μA。Ag/n ZnO紫外探测器有明显的光响应特性和较高的量子效率,在 366nm波长处,光响应度达到最大值 0. 161A/W,量子效率为 54. 7%。
ZnO has been studied extensively for several applications, such as surface-acoustic-wave devices, ultraviolet light-emitting devices, laser diodes and gas sensors. Apart from these, high quality ZnO films are promising for UV photodetector application due to their wide and direct band gap and large photoresponse. Compared with photoconductive detector, Schottky type photodetectors are more attractive due to their high speed and low noise performance. Previously reported Schottky barrier UV sensitive photodiodes exhibited low quantum efficiency due to a large amount of recombination centers in the polycrystalline ZnO layers. In this paper, hexagonal microtube ZnO was firstly grown on single crystal p-Si(111) substrates by hydrothermal method. The Ag film electrodes was deposited on ZnO by planar magnetron sputtering, therefore Ag/n-ZnO UV photodetector was fabricated. The characteristic of dark- and photo-current of Ag/n-ZnO Schottky UV photodetector, the UV photoresponse and the quantum efficiency of the detector were also investigated. The results of testing indicate that there is a good Schottky behavior between Ag and microtube ZnO, and an effective barrier height is 0.35 eV. Dark current was very small,without illumination. Under illumination using monochromatic light with a wavelength of 365 nm, photogenerated current arrived at 25.6 and 57.9 μA, at a bias of 5 V and 9 V,respectively. A evident wide-range spectral responsivity and higher quantum efficiency of (Ag/n-ZnO) detector were observed. The maximum photo-responsibility of 0.161 A/W and the quantum efficiency of (54.7%) were obtained at wavelength of 366 nm. Therefore, the hexagonal microtube ZnO is suitable to (apply) for UV photodetector.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2005年第1期135-138,共4页
Chinese Journal of Luminescence
基金
国家"973"项目(51310Z09 4)
国家自然科学基金重大项目(60390073)资助项目
关键词
六棱微管ZnO
肖特基势垒结
紫外光探测器
I-V特性
光响应度
置子效率
hexagonal microtube ZnO
Schottky barrier
UV photodetector
I-V characteristic
spectral (responsivity
) quantum efficiency
