Extended Tight-Binding and Thermochemical Modeling of III-Nitride Heterostructures at Any Temperature and Pressure

Modelling of Band Offsets in II-VI Heterostructures

“…(8) for various heterojunctions. Predicted valence band offsets are given in the first column of Table 2 for various interfaces, which are compared with the corresponding values of p-p extended tight binding model (ETB3) [3], model solid theory [9], linear muffin thin orbital model (LMTO) [10], and the first principles electronic structure model (FPES) [11] against the experimental data [2], with excellent agreement. Predicted valence band offsets are given in the first column of Table 2 for various interfaces, which are compared with the corresponding values of p-p extended tight binding model (ETB3) [3], model solid theory [9], linear muffin thin orbital model (LMTO) [10], and the first principles electronic structure model (FPES) [11] against the experimental data [2], with excellent agreement.…”

“…where E g; av ¼ ½E gG þ 4E gL þ 3E gX =8 is the average bandgap, defined as E g; av ¼ E c; av À E v; av , where E c; av ¼ ½E cG þ 4E cL þ 3E cX =8 is the average conduction band and E v; av ¼ E v À D s =3 is the average of the heavy hole, light hole and spin-orbit split-off valence bands and E v is the top of the valence band at the center of the Brillouin zone, obtained by using the p-p tight binding theory [3] or the sp 3 tight binding theory [4]. Since E 0 ¼ ðE a þ E b Þ=2 can be calculated from the tight binding parameters using Eqs.…”

“…(10) with those of p-p tight binding model (ETB3) [3], model solid theory [9], linear muffin thin orbital model (LMTO) [10], and first principles electronic structure model (FPES) [11], against the measured valence band offsets. (2) and ETB2 due to Eq.…”

“…[2]). Most of the models, despite their accuracies in some cases, can only give limited insight into the development of heterojunction devices operating at high temperatures and pressures [3,4]. In this work, the valence band energies are determined using the sp 3 tight binding model, which includes the overlapping of sp 3 hybrids of adjacent atoms and the interaction between the bonding and antibonding states at high symmetry points.…”

“…where e 1 the optical dielectric constant of the constituent semiconductors and DE gi ðT; PÞ is the bandgap difference at any temperature, pressure and alloy composition [3,4,6]. The strain effects on band offsets are calculated by substituting P ¼ À3B s E sk for substrate (material B) and P ¼ À2C f B f E k for epitaxial film (material A) in Eqs.…”