Stability, electronic and defect levels induced by substitution of Al and P pair in 4H–SiC. (July 2020)

• Record Type: Journal Article
• Authors: Igumbor, E.; Dongho-Nguimdo, G.M.; Mapasha, R.E.; Omotoso, E.; Meyer, W.E.
• Is Part Of: Journal of physics and chemistry of solids. Volume 142(2020)
• Publication Date: 2020-07
• Subjects: Defect -- Formation energy -- Charge state -- Substitution pair; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2020.109448
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: Impurities play a major role in identifying the most enhanced defect-levels induced in 4H–SiC. Among the important n - and p -type dopants in SiC are the P and Al, respectively. The P and Al dopants modify the 4H–SiC electronic structure and induce notable defect-levels which may influence the host's performance. In this report, the Heyd, Scuseria and Ernzerhof hybrid functional was used to predict the energetic, stability, electronic properties and defect levels induced by P and Al substitutional pair in 4H–SiC. The PSi AlSi configurations of the P and Al substitutional pair in 4H–SiC in its neutral charge state, under equilibrium conditions, is more energetically favourable with a formation energy of 0.21 eV. The substitution of P and Al pair in 4H–SiC for the different configurations are energetically stable with respect to their binding energies. The PSi AlC configuration with respect to its binding energy shown low tendency to dissociate into a non-interacting defects with an energy of 4.00 eV compared to other defects. Defect levels were induced by the P and Al substitutional pair in 4H–SiC. A deep ( + 2/ + 1) level and shallow ( + 1/0) and (0/ − 1) levels were predicted for the PC AlC and PC AlSi . In all defect configurations, the (0/ − 1) defect level was found to be close to the conduction band minimum. The results of this report provide frontier insight for the synthesis of the substitution of P and Al pair in 4H–SiC. Highlights: The double substitution of P and Al in 4H–SiC occurs with relatively low energy and stable with respect to their binding energies. The substitution of P/Al on Si sites is under equilibrium conditions, more energetically favourable than other defects. Defect levels were induced by the P and Al substitutional pair in 4H–SiC. All the acceptor levels induced in the band gap of 4H–SiC are always shallow and close to the conduction band minimum. The results of this report will provide more frontier insight for the synthesis of the substitution of P and Al pair in 4H–SiC.