The electrons in graphene behave as Dirac Fermions and have a very high mobility. The linear electronic band structure of graphene and the low density of states near the Dirac points allow that the Fermi level of graphene is highly tunable. The junction formed by graphene and semiconductor is ultrashallow and near the graphene layers. Those merits make graphene/semiconductor heterostructure highly efficient for optoelectronic devices. We have realized plasmon enhanced graphene/GaN light emitting diodes through inserting Ag nanodots into the interface between graphene and GaN1. Through introducing the ideas of plasmon enhanced absorption, photo-induced doping and field effect, we have achieved a high efficient graphene/GaAs solar cell with a power conversion efficiency (PCE) of 18.5%, which can be further improved to 23.8% according to the simulations2,3. We propose that the PCE of graphene solar cell can exceed the value of 30% under the sustainable optimization of the Fermi level tuning and other techniques4. Graphene solar cell has a bright future for industrial applications. Graphene is also a monolayer of honeycomb carbon, the interface between graphene and piezoelectronic material can largely influences the electronic properties of graphene. Through understanding the interaction between water, graphene and piezoelectronic substrate, we have achieved the electricity output through flowing DI water over graphene/piezoelectronic material heterestructure6. 

References 

1, Z. Q. Wu, Y. H. Lu, W. L. Xu, Y. J. Zhang, J. F. Li, S. S. Lin*, Surface plasmon   enhanced graphene/p-GaN heterostructure light-emittingdiode by Ag nano-particles, Nano Energy 30, 362 (2016).

2, S. S. Lin*, Z. Q. Wu, X. Q. Li, Y. J. Zhang, S. J. Zhang, P. Wang, R. Panneerselvam, J. F. Li*, Stable 16.2% Efficient Surface Plasmon-Enhanced Graphene/GaAs Heterostructure Solar Cell, Adv Energy Mater, 6, 1600822 (2016).

3, X. Q. Li, W. C. Chao, S. J. Zhang, Z. Q. Wu, P. Wang, Z. J. Xu, H. S. Chen, W. Y. Yin, H. K. Zhong, S. S. Lin*, 18.5% efficient graphene/GaAs van der Waals heterostructure solar cell, Nano Energy, 9, 310 (2015).

4, S. S. Lin*, Z. Q. Wu, J. Xu, S. R. Feng, J. F. Li, High performance Graphene/semiconductor van der Waals Heterostructure Optoelectronic Devices, Nano Energy, https://doi.org/10.1016/j.nanoen.2017.07.036

5, H. K. Zhong, J. Xia, F. C. Wang, H. S. Chen, H. A. Wu, S. S. Lin*, Graphene-Piezoelectric Material Heterostructure for Harvesting Energy from Water Flow, Adv. Functional Mater. 27, 1604226 (2017) 

The electrons in graphene behave as Dirac Fermions and have a very high mobility. The linear electronic band structure of graphene and the low density of states near the Dirac points allow that the Fermi level of graphene is highly tunable. The junction formed by graphene and semiconductor is ultrashallow and near the graphene layers. Those merits make graphene/semiconductor heterostructure highly efficient for optoelectronic devices. We have realized plasmon enhanced graphene/GaN light emitting diodes through inserting Ag nanodots into the interface between graphene and GaN1. Through introducing the ideas of plasmon enhanced absorption, photo-induced doping and field effect, we have achieved a high efficient graphene/GaAs solar cell with a power conversion efficiency (PCE) of 18.5%, which can be further improved to 23.8% according to the simulations2,3. We propose that the PCE of graphene solar cell can exceed the value of 30% under the sustainable optimization of the Fermi level tuning and other techniques4. Graphene solar cell has a bright future for industrial applications. Graphene is also a monolayer of honeycomb carbon, the interface between graphene and piezoelectronic material can largely influences the electronic properties of graphene. Through understanding the interaction between water, graphene and piezoelectronic substrate, we have achieved the electricity output through flowing DI water over graphene/piezoelectronic material heterestructure6. 

References 

1, Z. Q. Wu, Y. H. Lu, W. L. Xu, Y. J. Zhang, J. F. Li, S. S. Lin*, Surface plasmon   enhanced graphene/p-GaN heterostructure light-emittingdiode by Ag nano-particles, Nano Energy 30, 362 (2016).

2, S. S. Lin*, Z. Q. Wu, X. Q. Li, Y. J. Zhang, S. J. Zhang, P. Wang, R. Panneerselvam, J. F. Li*, Stable 16.2% Efficient Surface Plasmon-Enhanced Graphene/GaAs Heterostructure Solar Cell, Adv Energy Mater, 6, 1600822 (2016).

3, X. Q. Li, W. C. Chao, S. J. Zhang, Z. Q. Wu, P. Wang, Z. J. Xu, H. S. Chen, W. Y. Yin, H. K. Zhong, S. S. Lin*, 18.5% efficient graphene/GaAs van der Waals heterostructure solar cell, Nano Energy, 9, 310 (2015).

4, S. S. Lin*, Z. Q. Wu, J. Xu, S. R. Feng, J. F. Li, High performance Graphene/semiconductor van der Waals Heterostructure Optoelectronic Devices, Nano Energy, https://doi.org/10.1016/j.nanoen.2017.07.036

5, H. K. Zhong, J. Xia, F. C. Wang, H. S. Chen, H. A. Wu, S. S. Lin*, Graphene-Piezoelectric Material Heterostructure for Harvesting Energy from Water Flow, Adv. Functional Mater. 27, 1604226 (2017)