Enhanced P-Type GaN Conductivity by Mg Delta Doped AlGaN/GaN Superlattice Structure.

Ying Zhao,Jinjuan Du,Yue Hao,Shengrui Xu,Lansheng Feng,Jincheng Zhang,Yachao Zhang,Xiaomeng Fan,Chunfu Zhang,Hongchang Tao,Ruoshi Peng

doi:10.3390/ma14010144

Abstract

A method of combining the AlGaN/GaN superlattices and Mg delta doping was proposed to achieve a high conductivity p-type GaN layer. The experimental results provided the evidence that the novel doping technique achieves superior p-conductivity. The Hall-effect measurement indicated that the hole concentration was increased by 2.06 times while the sheet resistivity was reduced by 48%. The fabricated green-yellow light-emitting diodes using the achieved high conductivity p-type GaN layer showed an 8- and 10-times enhancement of light output power and external quantum efficiency, respectively. The subsequent numerical calculation was conducted by using an Advanced Physical Model of Semiconductor Device to reveal the mechanism of enhanced device performance. This new doping technique offers an attractive solution to the p-type doping problems in wide-bandgap GaN or AlGaN materials.

Highlights

III-Nitride and related alloys are attractive materials due to their immense potential in optoelectronic applications including the ultraviolet and visible range [1,2,3,4,5,6,7,8,9]
In order to investigate the influence of novel doping method on the p-conductivity of GaN film, two p-GaN structures were grown by AIXTRON CRUIS I metal-organic chemical vapor deposition (MOCVD) system on the c-plane patterned sapphire substrates (PSS)
In order to clarify the mechanism of novel doping methods enhanced the p-conductivity of GaN film, the calculated hole concentrations distributions and energy band diagrams of sample B are given in Figure 5, which are performed by the commercial simulation software APSYS

Summary

Introduction

III-Nitride and related alloys are attractive materials due to their immense potential in optoelectronic applications including the ultraviolet and visible range [1,2,3,4,5,6,7,8,9]. A method of combining the AlGaN/GaN SLs and Mg delta doping is proposed to achieve high conductivity p-type GaN, which is realized by accepter doping in the whole p-type region but increasing the doping concentration at the AlGaN/GaN interface to improve the p-type conductivity. This method resolves the problem of existence of high resistance areas of discontinuous doping method, and utilizes the polarized electric field adequately. A systematical study about the influence of the new p-type technique on the performance of green-yellow light emitting diodes (LED) is performed both numerically and experimentally

Materials and Methods

Findings

Conclusions