A dielectric‐constant‐controlled tunnel junction for III‐nitride light‐emitting diodes. Issue 6 (23rd March 2017)

• Record Type: Journal Article
• Authors: Li, Luping; Shi, Qiang; Tian, Kangkai; Chu, Chunshuang; Fang, Mengqian; Meng, Ruilin; Zhang, Yonghui; Zhang, Zi‐Hui; Bi, Wengang
• Is Part Of: Physica status solidi. Volume 214:Issue 6(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-03-23
• Subjects: dielectric‐constant‐controlled tunnel junction -- hole injection efficiency -- LED -- quantum efficiency; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201600937
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : Due to the low hole mobility and the unsatisfying p‐type doping efficiency, the p‐type layer has a low effective hole concentration and a large electrical resistivity that result in poor hole injection efficiency and significant current crowding effect for III‐nitride light‐emitting diodes (LEDs). In this work, we report a III‐nitride LED architecture comprising a dielectric‐constant‐controlled tunnel junction to improve both the current spreading effect and the hole injection efficiency. The dielectric‐constant‐controlled tunnel junction is an n + ‐GaN/AlGaN/p + ‐GaN heterojunction, in which the dielectric constant for the AlGaN layer is smaller than that for the GaN layer, and therefore, compared to the conventional n + ‐GaN/p + ‐GaN homojunction, the electric field within the tunnel junction is increased and hence, the hole injection can be substantially enhanced if the n + ‐GaN/AlGaN/p + ‐GaN heterojunction is properly designed. Furthermore, the proposed device can better spread the current compared to the LED without a tunnel junction. As a result, the internal quantum efficiency has been improved for the LED possessing the dielectric‐constant‐controlled tunnel junction.