n-Ga_(2)O_(3)/p-GaAs异质结日盲紫外探测器制备

Preparation of n-Ga_(2)O_(3)/p-GaAs Heterojunction Solar-blind UV Photodetectors

采用金属有机化学气相沉积(MOCVD)工艺在p-GaAs(100)衬底上外延了Ga_(2)O_(3)薄膜并制备了n-Ga_(2)O_(3)/p-GaAs异质结日盲紫外探测器。通过X射线衍射仪、原子力显微镜、场发射扫描电子显微镜等方法对Ga_(2)O_(3)薄膜表面形貌、晶体质量进行了测试与分析。结果表明,Ga_(2)O_(3)薄膜呈单一晶向,薄膜表面平整且为Volmer-Weber模式外延。测试表明,n-Ga_(2)O_(3)/p-GaAs异质结探测器具有明显的整流特性。器件在5 V反向偏压和紫外光(254 nm)照射下实现了超过3.0×10^(4)的光暗电流比、7.0 A/W的响应度、3412%的外量子效率、4.6×10^(13)Jones的探测率。我们利用TCAD软件对器件结构进行仿真,得到了器件内的电场分布和能带结构,并分析了器件的工作原理。该异质结探测器性能较好,制造工艺简单,为Ga_(2)O_(3)超灵敏日盲紫外探测器的研制提供了新途径。

Ga_(2)O_(3) thin films were deposited on p-GaAs(100)substrates by metal-organic chemical vapor deposition(MOCVD)process for the preparation of n-Ga_(2)O_(3)/p-GaAs heterojunction solar-blind UV photodetectors(PDs).The surface morphology and crystal quality of Ga_(2)O_(3) thin films were measured and analyzed by X-ray diffractometer,atom⁃ic force microscope,and field emission scanning electron microscope.The results showed that the Ga_(2)O_(3) thin films exhibited a single crystal orientation,with a flat surface and Volmer-Weber mode epitaxy.The characterization indi⁃cated that the n-Ga_(2)O_(3)/p-GaAs heterojunction detector exhibited an obvious rectification characteristic.The device achieves a photo-dark current ratio of more than 3.0×10^(4),a responsivity of 7.0 A/W,an external quantum efficien⁃cy of 3412%,and a detectivity of 4.6×10^(13)Jones under 5 V reverse bias and UV(254 nm)illumination.The device structure was simulated using TCAD software,obtaining the electric field distribution and band structure inside the device,and the working principle of the device was analyzed.The performance of the heterojunction detector was ex⁃cellent and the manufacturing process was simple,providing a new avenue for the development of Ga_(2)O_(3) ultrasensi⁃tive solar-blind UV photodetectors.