Splitting of close N-Al donor-acceptor-pair spectra in 3C-SiC

Abstract

Discrete series of lines have been observed for many years in N‐Al DAP (Donor Acceptor Pair) spectra in 3C‐SiC. Unfortunately, up to now, there has been no quantitative analysis for the splitting of lines in a given shell. This is done in this work for N‐Al DAP spectra in 3C‐SiC. The samples were non‐intentionally doped 3C‐SiC layers grown by CVD on a VLS seeding layer grown on a 6H‐SiC substrate. From low temperature photoluminescence measurements, strong N‐Al DAP emission bands were observed and, on the high energy side of the zero‐phonon line, we could resolve a series of discrete lines coming from close pairs. Comparing with literature data, we show that the splitting energy for a given shell is constant and, to explain this shell substructure, we consider the non equivalent sets of sites for a given shell. Results are discussed in terms of the ion‐ion interaction containing third and forth multipole terms.