Gold-patched graphene nano-stripes for high-responsivity and ultrafast photodetection from the visible to infrared regime  

作　　者：Semih Cakmakyapan Ping Keng Lu Aryan Navabi Mona Jarrahi 

机构地区：[1]Electrical Engineering Department,University of California Los Angeles,Los Angeles,CA 90095,USA

出　　处：《Light(Science & Applications)》2018年第1期872-880,共9页光（科学与应用)（英文版）

基　　金：support from the Department of Energy(grant#DE-SC0016925)。

摘　　要：Graphene is a very attractive material for broadband photodetection in hyperspectral imaging and sensing systems.However,its potential use has been hindered by tradeoffs between the responsivity,bandwidth,and operation speed of existing graphene photodetectors.Here,we present engineered photoconductive nanostructures based on goldpatched graphene nano-stripes,which enable simultaneous broadband and ultrafast photodetection with high responsivity.These nanostructures merge the advantages of broadband optical absorption,ultrafast photocarrier transport,and carrier multiplication within graphene nano-stripes with the ultrafast transport of photocarriers to gold patches before recombination.Through this approach,high-responsivity operation is realized without the use of bandwidth-limiting and speed-limiting quantum dots,defect states,or tunneling barriers.We demonstrate highresponsivity photodetection from the visible to infrared regime(0.6 A/W at 0.8μm and 11.5 A/W at 20μm),with operation speeds exceeding 50 GHz.Our results demonstrate improvement of the response times by more than seven orders of magnitude and an increase in bandwidths of one order of magnitude compared to those of higherresponsivity graphene photodetectors based on quantum dots and tunneling barriers.

关 键 词：RESPONSIVITY REGIME VISIBLE 

分 类 号：TN2[电子电信—物理电子学]