基于InAs/GaAs量子点-石墨烯复合结构的肖特基光电探测器研究

Study of Schottky Photodetector Based on InAs/GaAs Quantum Dot-Graphene Hybrid Structure

石墨烯具有电子迁移率高、透过率高(T≈97.7%)且费米能级可调的特性。砷化镓的电子迁移率比硅的大5到6倍。引入砷化铟量子点后,光电探测器具有低暗电流、高工作温度、高响应率和探测率的特点,因而可被用于制备响应快、量子效率高和光谱宽的光电探测器。对基于InAs/GaAs量子点-石墨烯复合结构的肖特基结的Ⅰ-Ⅴ特性和光电响应进行了研究。结果表明,在0 V偏压下,该器件在400 nm^950 nm均有响应,峰值响应率可达0.18 A/W;在反向偏压下,器件的峰值响应率可达到0.45 A/W。通过对暗电流随温度变化的特性进行分析,得到了InAs/GaAs量子点一石墨烯肖特基结在室温附近以及80 K附近的势垒高度。

Graphene has the features of high electron mobility, high transmittance （T = 97.7%） and adjustable Fermi energy. The electron mobility of GaAs is 5 to 6 times higher than that of silicon. After introducing indium arsenide quantum dots, the photoelectric detector will has the features of low dark current, high operation temperature, high responsivity and high detectivity. Therefore, it can be used to fabricate fast, high quantum efficiency and wide spectrum photoelectric detectors. The I-V characteristics and photoresponse of a Schottky junction based on a graphene-InAs/GaAs quantum dot hybrid structure are studied. The results show that at the bias voltage of 0 V, the device shows its photoresponse in the wavelength range 400 nm to 950 nm with the peak response of 0.18 A/W. At the reverse bias voltage, its peak response can reach 0.45 A/W. Through the analysis of the temperature dependence of dark current, the barrier height of the Schottky junction at room temperature and 80 K is obtained.