高比探测率和高速石墨烯/n-GaAs复合结构的光电探测器

混合结构的石墨烯/半导体光电晶体管因其超高的响应度而备受关注。然而,该类光电晶体管通过源-漏电极测试得到的比探测率(D*)容易受到1/f噪声的限制。本文制备了混合结构的石墨烯/GaAs光电探测器,通过源-栅电极测得D*大约为1.82×10¹¹ Jones,与通过源-漏电极测量相比,D*提高了约500倍。这可归因于界面上肖特基势垒对载流子俘获和释放过程的屏蔽作用。此外,探测器的上升时间和下降时间分别是4 ms和37 ms,响应速度相应地提高了2个数量级。该工作为制备高比探测率和高速的光电探测器提供了一种新的思路。

Hybrid graphene/n-GaAs photodiodes with high specific detectivity and high speed

Hybrid graphene/semiconductor phototransistors have attracted great attention because of their ultrahigh responsivity.However,the specific detectivity(D*)for such hybrid phototransistors obtained from source-drain electrodes is assumed to be 1/f noise.In this paper,D*of~1.82×10¹¹ Jones was achieved from source-gate electrodes.Compared with the same device which was measured from source-drain electrodes,D*was improved by~500 times.This could be attributed to the carrier trapping and detrapping processes having been screened by the Schottky barrier at the interface.The rise and decay times were 4 ms and 37 ms,respectively.The temporal response speed also correspondingly improved by~2 orders of magnitude.This work provides an alternative route toward light photodetectors with high specific detectivity and speed.