基于石墨烯/铟砷量子点/砷化镓异质结新型光电探测器（英文）

研究了一种石墨烯/铟砷量子点/砷化镓界面形成的异质结探测器的暗电流特性以及光电响应性质.虽然石墨烯具有很高的电子迁移率,但受限于较低的光子吸收率,使其在光电探测领域的应用受到了限制.而半导体量子点具有量子效率高,光吸收能力强等独特优点.于是利用石墨烯-砷化铟量子点-砷化镓异质结结构制备了一种新型光电探测器.并对该探测器的响应率、I-V 特性曲线、暗电流特性、探测率、开关比等关键性能进行了研究.其在637 nm 入射光情况下的响应率、探测率以及开关比可分别达到为17. 0 mA/W、2. 3 × 1010cmHz1 /2 W- 1 和1 × 103 .而当入射光为近红外波段的940 纳米时,响应率进一步增加到了207 mA/W.同时,还证实了该器件的暗电流、肖特基势垒高度和理想因子对温度的都具有较高的依赖性都较强.

A novel photodetector based on Graphene/InAs quantum dots/GaAs hetero-junction

Due to the ultra-high electron mobility,graphene has been proposed as a prospective candidate for the photodetection. Nevertheless the relatively low photo absorption limits its potential application. On the other hand, the semiconductor quantum dots has exhibited high quantum efficiency and strong optical absorption. A novel photodetector by the incorporation of graphene with InAs quantum dots on GaAs substrate has been proposed. The performance of the fabricated photodetector,such like photoresponse,dark current,and time response,have been extensively studied. The photodetector based on graphene /InAs QDs /GaAs hybrid hetero-junction demonstrated that for the visible range of 637 nm a responsivity of about 17. 0 mA /W,and detectivity of 2. 3 × 10^10 cm Hz1 /2 W - 1 , with an on /off ratio of about 1 × 10^3 could be achieved. For the near infrared range of 940 nm,an even higher responsivity of of 207 mA /W has been obtained. Moreover a stronger dependence of dark current,Schottky barrier height and ideality factor on temperature has also been observed.