Defect-Induced Luminescence Quenching of 4H-SiC Single Crystal Grown by PVT Method through a Control of Incorporated Impurity Concentration

Seul-Ki Kim,Eun Young Jung,Myung-Hyun Lee

doi:10.3390/compounds2010006

Abstract

The structural defect effect of impurities on silicon carbide (SiC) was studied to determine the luminescence properties with temperature-dependent photoluminescence (PL) measurements. Single 4H-SiC crystals were fabricated using three different 3C-SiC starting materials and the physical vapor transport method at a high temperature and 100 Pa in an argon atmosphere. The correlation between the impurity levels and the optical and fluorescent properties was confirmed using Raman spectroscopy, X-ray diffraction, inductively coupled plasma atomic emission spectroscopy (ICP-OES), UV-Vis-NIR spectrophotometry, and PL measurements. The PL intensity was observed in all three single 4H-SiC crystals, with the highest intensities at low temperatures. Two prominent PL emission peaks at 420 and 580 nm were observed at temperatures below 50 K. These emission peaks originated from the impurity concentration due to the incorporation of N, Al, and B in the single 4H-SiC crystals and were supported by ICP-OES. The emission peaks at 420 and 580 nm occurred due to donor–acceptor-pair recombination through the incorporated concentrations of nitrogen, boron, and aluminum in the single 4H-SiC crystals. The results of the present work provide evidence based on the low-temperature PL that the mechanism of PL emission in single 4H-SiC crystals is mainly related to the transitions due to defect concentration.

Highlights

Accepted: 21 February 2022Silicon carbide (SiC) has attracted the attention of many researchers due to its outstanding electrical, mechanical, and thermal properties
Process and a visible-light-emitting luminescence of a fluorescent 4H-silicon carbide (SiC) sample excited by a 325 nm pulsed laser source
The 4H-SiC crystal that was grown was cut in the form of a wafer and was subjected to slicing and polishing in a direction perpendicular to the c-axis on the Si face before the PL measurement

Summary

Introduction

Silicon carbide (SiC) has attracted the attention of many researchers due to its outstanding electrical, mechanical, and thermal properties. SiC has been used in many industries for power devices and optoelectronic applications [1–8]. There are more than 200 polytypes of Si-C, with cubically (3C-SiC) and hexagonally (4H-SiC or 6H-SiC) modified compounds being the most used. The existence of polytypes implies that many different stable atomic arrangements and symmetries can be obtained, including hexagonal, cubic, and rhombohedral arrangements [6,7]. A thorough analysis of the carrier recombination mechanisms in SiC is needed to understand the underlying physics of the luminescence phenomena for industrial applications. Photoluminescence (PL) is a standard method for characterizing the emission properties of semiconductor materials and can provide information about defect-related carrier transport dynamics [8]

Methods

Results

Conclusion