Calculation Method for the Bandgap of Antimonide Based Multicomponent Alloys

As the most important material parameter of semiconductor, bandgap is necessary to be investigated to meet the design requirements of the high-performance optoelectronic devices. A new method of is proposed to calibrate the bandgap of antimonide based multi-component alloys with considering the effect of spin-orbit splitting off bands and the doublet degeneracy of valance band on the bandgaps of Sb-containing materials. A correction factor is introduced in the conventional calculation, and the spin-orbit splitting method is proposed. Besides, the In_xGa_{1-x}As_ySb_{1-y} films with different compositions are grown on GaSb substrates by molecular beam epitaxy, and the corresponding bandgaps are obtained by photoluminescence to test the accuracy and reliability of this new method. An error rate analysis reveals that the α calculated by the spin-orbit splitting correction method is decreased to 2%, almost one order of magnitude smaller than the Moon method, which means that the new method can calculate the antimonide multicomponent more accurately with some applicability. This work can give a reasonable interpretation for the reported results and beneficial to tailor the antimonides properties and optoelectronic devices.