Bright Multicolored Photoluminescence of Hybrid Graphene/Silicon Optoelectronics

Abstract

Graphene does not possess a band gap, and hot carrier relaxation in graphene is an ultrafast processs. This leads to a very low emission efficiency of graphene. We demonstrate bright multicolored frequency-upconverted photoluminescence from graphene via three-photon absorption by femtosecond laser injection at a communication wavelength 1.57 μm. The broadband and multiwavelength emission from graphene is based on the model of ultrafast electron–hole pair recombination and asymmetrical energized electron–hole radiation recombination in graphene. Furthermore, we show photoluminescence variation with blue light emission in the graphene/silicon hybrid system, with 2–3 orders of emission efficiency increase. The results demonstrate hot carrier multiplication and hot carrier scattering in graphene and could help to study the population inversion and broadband lasing of graphene.