Hot carriers assisted mixed-dimensional graphene/MoS2/p-GaN light emitting diode

The exploration of two-dimensional (2D) materials in highly performance optoelectronic device is critical for the practical applications. Traditionally, GaN related semiconductors uses complicated multiple quantum wells to increase the overlap of electron and hole waves for highly efficient light emitting diode (LED). In this work, through designing the Graphene/MoS 2 heterostructure for increasing the hot electron lifetime and subsequently enhancing the process of carrier multiplication (CM), we successfully realize the highly efficient Graphene/MoS 2 /p-GaN LED with external quantum efficiencies (EQE) of 15.89% under 0.625 mA/mm 2 . Compared with the Graphene/p-GaN LED device, the addition of MoS 2 leads to stronger light output and the maximum EQE increased by 61%. The energy bands alignment between MoS 2 and GaN squeezes the hole at the MoS 2 layer, when the numbers of holes are increased by graphene as a result of CM effect, which recombines with electron at the surface of GaN defects resulting in the strong light output at reversed bias. We believe that this work will bring a brand new insight of realizing high efficient 2D materials based LED and optoelectronic devices. • We successfully realize hot carriers assisted mixed-dimensional Graphene/MoS 2 /p-GaN LED. • The CM effect in the Graphene effectively increases the accumulation of carriers at the junction area between the MoS 2 and p-GaN. • The radiative recombination on the surface of p-GaN improve the EQE.