InGaN-based vertical light-emitting diodes with acid-modified graphene transparent conductor and highly reflective membrane current blocking layer

Vertical light-emitting diodes (VLEDs) with a highly reflective membrane (HRM) as current blocking layer (CBL) and a graphene transparent conductive layer (TCL) have been fabricated and characterized. High reflectance of HRM and high transmittance of graphene ensure less loss of the optical power. The VLEDs show improved optical output and less efficiency droop, thanks to the current spreading effect of HRM CBL and graphene TCL by preventing current crowding under the top electrode and thus increasing the internal and external quantum efficiency. With further acid modification, forward electrical characteristics of VLEDs are improved.