On an Approximation for the Energy Gap at Γ of A² B⁴ C⁵₂ Compounds with Chalcopyrite Structure

Abstract

Due to the small tetragonal distortion described by the parameters Z = 2 -a l(dl/2) 4 d )

Electronic structure, chemical bonding and optical properties of the nonlinear optical crystal ZnGeP2by first-principles calculations

“…According to figure 1 and table 2, the top of the valence band locates at Γ point and the bottom of the conduction band minimum locates at N point, therefore, we can say that this compound has an indirect band gap at N-point G  N , ) the obtained nature of the band gap is obviously opposite to the result reported in the latest literature [24]. The calculated indirect band gap has a value of 1.222 eV, it can be confirmed that the calculated energy gap is underestimated by comparison with the experimental data [12,43,44]. It is well known that the band gap calculated by DFT is smaller than that obtained from experiments, this error being caused by the discontinuity of exchange-correlation energy [45].…”

Electronic structure of the ternary pnictide semiconductorsZnSiP2,ZnGeP2Jaffe1, Zunger2 1984Phys. Rev. B1114300View full textAdd to dashboardCite

“…We have Eg(pseudo) =I 3"-I 4", Eg(direct) =I 1, -I 4", and ECF --r5"-I 4". We use u =u, "~, (Table I) (2) r"" (2) cF r5@…”

“…(1) I g" a(")-C") bond (2) r," Ge, and Sn, respectively), reflecting an increase in the B' ' -C' ' bond length and reduced interaction along this series. This tendency also reflects the near resonance of the isolated Si and P orbital energies, and the progressive departure from this close matching as one goes to B" '=Ge, and finally to B" '=Sn with its deep and nearly chemically inert s orbitals.…”