Dynamics Studies of Nitrogen Interstitial in GaN from Ab Initio Calculations.

Huan He,Hongxiang Zong,Wenbo Liu,Chaohui He,Wenlong Liao,Dayin Tong,Lin Yang,Pengbo Zhang,Hang Zang

doi:10.3390/ma13163627

Abstract

Understanding the properties of defects is crucial to design higher performance semiconductor materials because they influence the electronic and optical properties significantly. Using ab initio calculations, the dynamics properties of nitrogen interstitial in GaN material, including the configuration, migration, and interaction with vacancy were systematically investigated in the present work. By introducing different sites of foreign nitrogen atom, the most stable configuration of nitrogen interstitial was calculated to show a threefold symmetry in each layer and different charge states were characterized, respectively. In the researches of migration, two migration paths, in-plane and out-of-plane, were considered. With regards to the in-plane migration, an intermediated rotation process was observed first time. Due to this rotation behavior, two different barriers were demonstrated to reveal that the migration is an anisotropic behavior. Additionally, charged nitrogen Frenkel pair was found to be a relatively stable defect complex and its well separation distance was about 3.9 Å. Part of our results are in good agreement with the experimental results, and our work provides underlying insights of the identification and dynamics of nitrogen interstitial in GaN material. This study of defects in GaN material is useful to establish a more complete theory and improve the performance of GaN-based devices.

Highlights

Gallium nitride (GaN) with a wide-gap (~3.4 eV) is an excellent semiconductor material.Nowadays, it has been widely used in visible–UV light emitting devices (LEDs) [1], laser diodes (LDs), 5G communications, and high power/frequency transistors [2,3] because of its outstanding properties, such as high electron mobility and high breakdown voltage
It has been widely used in visible–UV light emitting devices (LEDs) [1], laser diodes (LDs), 5G communications, and high power/frequency transistors [2,3] because of its outstanding properties, such as high electron mobility and high breakdown voltage
The results show that the differences differences between betweenthe theupward upwardand anddownward downwardpaths pathsininplane planeare aredue duetotothe therotation rotationbarrier

Summary

Introduction

Gallium nitride (GaN) with a wide-gap (~3.4 eV) is an excellent semiconductor material. Nowadays, it has been widely used in visible–UV light emitting devices (LEDs) [1], laser diodes (LDs), 5G communications, and high power/frequency transistors [2,3] because of its outstanding properties, such as high electron mobility and high breakdown voltage. In the process of GaN growth, the large lattice mismatch of GaN with its substrate (silicon carbide (SiC). There are varieties of defects appearing in the whole fabrication process, including native point defects and impurities, such as C, O, H, as well as dislocations [7,8].

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