Theory study on the bandgap of antimonide-based multi-element alloys

Abstract

In order to meet the design requirements of the high-performance antimonide-based optoelectronic devices, the spin–orbit splitting correction method for bandgaps of Sb-based multi-element alloys is proposed. Based on the analysis of band structure, a correction factor is introduced in the In[Formula: see text]Ga[Formula: see text]As[Formula: see text]Sb[Formula: see text] bandgaps calculation with taking into account the spin–orbit coupling sufficiently. In addition, the In[Formula: see text]Ga[Formula: see text]As[Formula: see text]Sb[Formula: see text] films with different compositions are grown on GaSb substrates by molecular beam epitaxy (MBE), and the corresponding bandgaps are obtained by photoluminescence (PL) to test the accuracy and reliability of this new method. The results show that the calculated values agree fairly well with the experimental results. To further verify this new method, the bandgaps of a series of experimental samples reported before are calculated. The error rate analysis reveals that the [Formula: see text] of spin–orbit splitting correction method is decreased to 2%, almost one order of magnitude smaller than the common method. It means this new method can calculate the antimonide multi-element more accurately and has the merit of wide applicability. This work can give a reasonable interpretation for the reported results and beneficial to tailor the antimonides properties and optoelectronic devices.