Novel BTlGaN semiconducting materials for infrared opto-electronic devices

BTlGaN quaternary alloys are proposed as new semiconductor materials for infrared opto-electronic applications. The structural and opto-electronic properties of zinc blende B_xTl_yGa_1?x?yN alloys lattice matched to GaN with (0 ? x and y ? 0.187) are studied using density functional theory (DFT) within full-potential linearized augmented plane wave (FP-LAPW) method. The calculated structural parameters such as lattice constant a₀ and bulk modulus B₀ are found to be in good agreement with experimental data using the new form of generalized gradient approximation (GGA-WC). The band gaps of the compounds are also found very close to the experimental results using the recently developed Tran–Blaha-modified Becke–Johnson (TB-mBJ) exchange potential. A quaternary B_xTl_yGa_1?x?yN is expected to be lattice matched to the GaN substrate with concentrations x = 0.125 and y = 0.187 allows to produce high interface layers quality. It has been found that B incorporation into BTlGaN does not significantly affect the band gap, while the addition of dilute Tl content leads to induce a strong reduction of the band gap, which in turn increases the emission wavelengths to the infrared region. The refractivity, reflectivity and absorption coefficient of these alloys were investigated. BTlGaN/GaN is an interesting new material to be used as active layer/barriers in quantum wells suitable for realizing advanced Laser Diodes and Light-Emitting Diodes as new sources of light emitting in the infrared spectrum region.