TY - JOUR
T1 - Non-destructive measurement of photoexcited carrier transport in graphene with ultrafast grating imaging technique
AU - Chen, Ke
AU - Yogeesh, Maruthi Nagavalli
AU - Huang, Yuan
AU - Zhang, Shaoqing
AU - He, Feng
AU - Meng, Xianghai
AU - Fang, Shaoyin
AU - Sheehan, Nathanial
AU - Tao, Tiger Hu
AU - Bank, Seth R.
AU - Lin, Jung Fu
AU - Akinwande, Deji
AU - Sutter, Peter
AU - Lai, Tianshu
AU - Wang, Yaguo
N1 - Publisher Copyright:
© 2016 Elsevier Ltd. All rights reserved.
PY - 2016/10/1
Y1 - 2016/10/1
N2 - Graphene has great potential for fabrication of ultrafast opto-electronics, in which relaxation and transport of photoexcited carriers determine device performance. Even though ultrafast carrier relaxation in graphene has been studied vigorously, transport properties of photoexcited carriers in graphene are largely unknown. In this work, we utilize an ultrafast grating imaging technique to measure lifetime (τr), diffusion coefficient (D), diffusion length (L) and mobility (μ) of photoexcited carriers in mono- and multi-layer graphene non-invasively. In monolayer graphene, D∼10,000 cm2/s and μ∼120,000 cm2/V have been observed, both of which decrease drastically in multilayer graphene, indicating that the remarkable transport properties in monolayer graphene originate from its unique Dirac-Cone energy structure. Mobilities of photoexcited carriers measured here are several times larger than the Hall and Field-Effect mobilities reported in literature (<15,000 cm2/V), due to the high energy of photoexcited carriers. Our results indicate the importance of obtaining monolayer graphene to realize high-performance graphene devices, as well as the necessity to use transport properties of photoexcited carriers for predicting the performance of graphene-based opto-electronics.
AB - Graphene has great potential for fabrication of ultrafast opto-electronics, in which relaxation and transport of photoexcited carriers determine device performance. Even though ultrafast carrier relaxation in graphene has been studied vigorously, transport properties of photoexcited carriers in graphene are largely unknown. In this work, we utilize an ultrafast grating imaging technique to measure lifetime (τr), diffusion coefficient (D), diffusion length (L) and mobility (μ) of photoexcited carriers in mono- and multi-layer graphene non-invasively. In monolayer graphene, D∼10,000 cm2/s and μ∼120,000 cm2/V have been observed, both of which decrease drastically in multilayer graphene, indicating that the remarkable transport properties in monolayer graphene originate from its unique Dirac-Cone energy structure. Mobilities of photoexcited carriers measured here are several times larger than the Hall and Field-Effect mobilities reported in literature (<15,000 cm2/V), due to the high energy of photoexcited carriers. Our results indicate the importance of obtaining monolayer graphene to realize high-performance graphene devices, as well as the necessity to use transport properties of photoexcited carriers for predicting the performance of graphene-based opto-electronics.
UR - http://www.scopus.com/inward/record.url?scp=84975048853&partnerID=8YFLogxK
U2 - 10.1016/j.carbon.2016.05.075
DO - 10.1016/j.carbon.2016.05.075
M3 - Article
AN - SCOPUS:84975048853
SN - 0008-6223
VL - 107
SP - 233
EP - 239
JO - Carbon
JF - Carbon
ER -