Band alignment of semiconductors from density-functional theory and many-body perturbation theory

Abstract

The band lineup, or alignment, of semiconductors is investigated via first-principles calculations based on density functional theory (DFT) and many-body perturbation theory (MBPT). Twenty-one semiconductors including C, Si, and Ge in the diamond structure, BN, AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs, InSb, ZnS, ZnSe, ZnTe, CdS, CdSe, and CdTe in the zinc-blende structure, and GaN and ZnO in the wurtzite structure are considered in view of their fundamental and technological importance. Band alignments are determined using the valence and conduction band offsets from heterointerface calculations, the ionization potential (IP) and electron affinity (EA) from surface calculations, and the valence band maximum and conduction band minimum relative to the branch point energy, or charge neutrality level, from bulk calculations. The performance of various approximations to DFT and MBPT, namely the Perdew-Burke-Ernzerhof (PBE) semilocal functional, the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional, and the GW approximation with and without vertex corrections in the screened Coulomb interaction, is assessed using the GW 1 approximation as a reference, where first-order vertex corrections are included in the self-energy. The experimental IPs, EAs, and band offsets are well reproduced by GW 1 for most of the semiconductor surfaces and heterointerfaces considered in this study. The PBE and HSE functionals show sizable errors in the IPs and EAs, in particular for group II-VI semiconductors with wide band gaps, but are much better in the prediction of relative band positions or band offsets due to error cancellation. The performance of the GW approximation is almost on par with GW 1 as far as relative band positions are concerned. The band alignments based on average interfacial band offsets for all pairs of 17 semiconductors and branch point energies agree with explicitly calculated interfacial band offsets with small mean absolute errors of both ∼0.1 eV, indicating a good overall transitivity of the band offsets. The alignment based on IPs from selected nonpolar surfaces performs comparably well in the prediction of band offsets at most of the considered interfaces. The maximum errors are, however, as large as 0.3, 0.4, and 0.7 eV for the alignments based on the average band offsets, branch point energies, and IPs, respectively. This margin of error should be taken into account when performing materials screening using these alignments.

First principle study of V-implantation in highly-doped silicon materials

“…For simplicity, discussions on the bulk-Si electronic structure were not deeply done herein as they have been extensively studied in the literature [19,51,52]. In short, our results are in agreement with the available data, which yields a theoretical band gap equal to 0.63 eV.…”

Interfacial insight in multi-junction metal oxide photoanodes for water-splitting applications

“…A recent comparative study has demonstrated that this approach predicts band off-sets in heterostructure interfaces rather well. [43] The CNLs have been calculated from the Kohn-Sham eigenvalues of the hybrid functional calculations by averaging the midgap energy over the first Brillouin zone and the topmost N valence bands and bottommost N conduction bands as described by Schleife et al [44] We have taken N as the number of primitive cells contained in the simulation cells employed in the DFT calculations (N = 3 for Fe 2 O 3 and N = 2 for TiO 2 ). The k-point mesh for the Brillouin zone sampling has been taken as described above for the hybrid functional calculations.…”

Nonempirical dielectric-dependent hybrid functional with range separation for semiconductors and insulators

“…delocalization error) prevalent in approximate xc functionals [9], which further contributes to improved band gaps as well as to more accurate lattice parameters and atomization energies [10]. Hence, hybrid functionals have been widely applied to the problems of point defects in solids [11][12][13] and of band alignments at interfaces [14][15][16][17][18].…”