Vertical pillar-superlattice array and graphene hybrid light emitting diodes.
We report a type of device that combines vertical arrays of one-dimensional (1D) pillar-superlattice (PSL) structures with 2D graphene sheets to yield a class of light emitting diode (LED) with interesting mechanical, optical, and electrical characteristics. In this application, graphene sheets coated with very thin metal layers exhibit good mechanical and electrical properties and an ability to mount, in a freely suspended configuration, on the PSL arrays as a top window electrode. Optical characterization demonstrates that graphene exhibits excellent optical transparency even after deposition of the thin metal films. Thermal annealing of the graphene/metal (Gr/M) contact to the GaAs decreases the contact resistance, to provide enhanced carrier injection. The resulting PSL-Gr/M LEDs exhibit bright light emission over large areas. The result suggests the utility of graphene-based materials as electrodes in devices with unusual, nonplanar 3D architectures.
Lee
Jung Min
JM
Division of Materials Science and Engineering, Hanyang University, Seoul 133-791, Korea.
Choung
Jae Woong
JW
Yi
Jaeseok
J
Lee
Dong Hyun
DH
Samal
Monica
M
Yi
Dong Kee
DK
Lee
Chul-Ho
CH
Yi
Gyu-Chul
GC
Paik
Ungyu
U
Rogers
John A
JA
Park
Won Il
WI