In:
Journal of Physics D: Applied Physics, IOP Publishing, Vol. 45, No. 14 ( 2012-04-11), p. 145101-
Abstract:
This paper describes a detailed systematic study based on the fabrication and performance of InGaN/GaN blue light-emitting diodes (LEDs) with multilayer graphene film as a current spreading electrode. Two facile approaches to improve the electrical coupling between graphene and p-GaN layer are demonstrated. Using chemical charge transfer doping, the work function (Φ) of graphene is tuned over a wide range from 4.21 to 4.93 eV with substantial improvements in sheet resistance ( R s ). Compared with pristine graphene, the chemically modified graphene on p-GaN yields several appealing characteristics such as low specific contact resistance (ρ c ) and minimized barrier height. In addition, insertion of a thin gold interlayer between graphene and p-GaN profoundly enhances the contact properties at the interface. Combining these two approaches in a single LED, the current spreading and thus the device forward voltage ( V f ) are considerably improved comparable to that of an LED fabricated with an indium tin oxide electrode. The importance of pre-metal deposition oxygen plasma treatment and rapid thermal annealing in improving the contact characteristics is also addressed.
Type of Medium:
Online Resource
ISSN:
0022-3727
,
1361-6463
DOI:
10.1088/0022-3727/45/14/145101
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
2012
detail.hit.zdb_id:
209221-9
detail.hit.zdb_id:
1472948-9