Evidence for Extraction of Photoexcited Hot Carriers from Graphene
Evidence for Extraction of Photoexcited Hot Carriers from Graphene
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DOI：
10.1021/nn302227r
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发表时间：
2012-08-01
期刊：
影响因子：
17.1
通讯作者：
Zhong, Zhaohui
中科院分区：
文献类型：
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作者：
Liu, Chang-Hua;Dissanayake, Nanditha M.;Zhong, Zhaohui
我们报告的非平衡热载流子提取石墨烯的栅极依赖的光电流研究的证据。飞秒脉冲激光激发的扫描光电流显示出与连续波（ON）激光激发相比不寻常的门依赖性。功率依赖性研究进一步证实，在金属/石墨烯接触处提取的光载流子是非平衡热载流子。热载流子提取被发现是最有效的狄拉克点附近的载流子寿命达到最大值。这些观测结果不仅为石墨烯的热载流子提取提供了证据，而且为石墨烯基热载流子光电子学打开了大门。
We report evidence of nonequilibrium hot carrier extraction from graphene by gate-dependent photocurrent study. Scanning photocurrent excited by femtosecond pulse laser shows unusual gate dependence compared with continuous wave (ON) laser excitation. Power dependence studies further confirm that the photocarriers extracted at the metal/graphene contact are nonequilibrium hot carriers. Hot carrier extraction is found to be most efficient near the Dirac point where carrier lifetime reaches a maximum. These observations not only provide evidence of hot carrier extraction from graphene but also open the door for graphene-based hot carrier optoelectronics.