Tuning Of Energy Band Gaps In Ternary Semiconductors

摘要

The first principle investigations on electronic structure of ABC_2 (A = Cd; B = Si, Ge, Sn; C= P, As) pnictides using the Tight Binding Linear Muffin Tin Orbital (TB-LMTO) method within the Atomic Sphere Approximation (ASA) is reported. Variation of Eg with pressure reveals the direct and pseudodirect natures of these compounds. CdSiP_2 shows a pseudo direct and CdGeP_2, CdSnP_2, CdSiAs_2, CdGeAs_2 and CdSnAs_2 show direct band gap natures. Semiconductor to metal transition at high pressures is observed. Metallisation volumes (V/Vo)_m and pressures (P_m), bulk modulus (B_o) and its pressure derivative ((B_o)~1) are reported. Correlation connecting Bo and the unit cell volume (Vo) is established.