ZnO nanorods/graphene/Ni/Au hybrid structures as transparent conductive layer in GaN LED for low work voltage and high light extraction. (December 2016)

• Record Type: Journal Article
• Authors: Xu, Kun; Xie, Yiyang; Ma, Huali; Du, Yinxiao; Zeng, Fanguang; Ding, Pei; Gao, Zhiyuan; Xu, Chen; Sun, Jie
• Is Part Of: Solid-state electronics. Volume 126(2016)
• Page Start: 5
• Page End: 9
• Publication Date: 2016-12
• Subjects: GaN -- Graphene -- LED -- ZnO -- Nanorods; Semiconductors -- Periodicals; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.sse.2016.09.021
• Languages: English
• ISSNs: 0038-1101

Abstract

Highlights: Graphene was used as transparency conductive layer to replace ITO in GaN LED. We showed a method to improve light exaction efficiency with low cost. We showed a method for forming ohmic contact between graphene and pGaN. The processing of the new method is compatible with current GaN LED process. Abstract: In this paper, by virtue of one-dimensional ZnO nanorods and two-dimensional graphene film hybrid structures, both the enhanced current spreading and enhanced light extraction were realized at the same time. A 1 nm/1 nm Ni/Au layer was used as an interlayer between graphene and pGaN to form ohmic contact, which makes the device have a good forward conduction properties. Through the comparison of the two groups of making ZnO nanorods or not, it was found that the 30% light extraction efficiency of the device was improved by using the ZnO nanorods. By analysis key parameters of two groups such as the turn-on voltage, work voltage and reverse leakage current, it was proved that the method for preparing surface nano structure by hydrothermal method self-organization growth ZnO nanorods applied in GaN LEDs has no influence to device's electrical properties. The hybrid structure application in GaN LED, make an achievement of a good ohmic contact, no use of ITO and enhancement of light extraction at the same time, meanwhile it does not change the device structure, introduce additional process, worsen the electrical properties.