Band structure doping effects

DOS analysis shows that both Ni and B character dominate the region around Ef, as also predicted by band structures. Doping by Co, Fe, or Ru causes a broadening (lattice disorder) and weakening (dilution effect) of the Ni-dominated peak which correlates reasonably well with the experimentally observed depression of Tc. A simple rigid-band+dilution model works adequately for low doping levels, but is inadequate for... 

This chapter summarizes the main theoretical approaches to model the porous silicon electronic band structure, comparing effective mass theory, semiempirical, and first-principles methods. In order to model its complex porous morphology, supercell, nanowire, and nanocrystal approaches are widely used. In particular, calculations of strain, doping, and surface chemistry effects on the band structure are discussed. Finally, the combined use of ab initio and tight-binding approaches to predict the band structure and properties of electronic devices based on porous silicon is put forward. 

We believe that the luminescence at 1.0 eV is due to a structural damage induced by ion implantation rather than to a chemical doping effect, since the spectrum does not depend on the chemical species of the ion. These centers may be similar to the vacancies induced by 3-MeV electron-beam irradiation, as reported by Troxell and Watkins (1979), who find donorlike and acceptorlike levels —0.1 eV from the band edges. 

V. L. Bonch-Bruevich, Effect of Heavy Doping on the Semiconductor Band Structure Donald Long, Energy Band Structures of Mixed Crystals of III-V Compounds Laura M. Roth and Petros N. Argyres, Magnetic Quantum Effects... 

It is reported that the band structure of ZnS doped with transition metal ions is remarkably different from that of pure ZnS crystal. Due to the effect of the doped ions, the quantum yield for the photoluminescence of samples can be increased. The fact is that because more and more electron-holes are excited and irradiative recombination is enhanced. Our calculation is in good correspondence with this explanation. When the ZnS (110) surface is doped with metal ions, these ions will produce surface state to occupy the valence band and the conduction band. These surface states can also accept or donate electrons from bulk ZnS. Thus, it will lead to the improvements of the photoluminescence property and surface reactivity of ZnS. 

V. L. Bonch-Bruevich, Effect of Heavy Doping on the Semiconductor Band Structure... 

Interfacial electron transfer across a solid-liquid junction can be driven by photoexcitation of doped semiconductors as single crystals, as polycrystalline masses, as powders, or as colloids. The band structure in semiconductors (281) makes them useful in photoelectrochemical cells. The principles involved in rendering such materials effective redox catalysts have been discussed extensively (282), and will be treated here only briefly. 

Fig. 2.11 Effect of n- and p-type doping on the band structure of a semiconductor (e.g. silicon).

As was discussed above, the absence of a kink in the nodal band below Ev [11] in NCCO, supports the possibility that it is also a real n-type cuprate. It is possible that the change in the sign of the TEP slope in NCCO with doping is an anomalous band-structure effect, probably associated with the peculiar evolution of its FS with doping, detected in ARPES [34], The position of the kink (below or above /q.) is determined by the inequality (11) between dq+ and d L, which is less susceptible to band-structure effects than the inequality (11) between bq+ and bq, determining the sign of the TEP slope. Anomalous behavior is observed also in the Hall constant of NCCO [32], which changes... 

N. K. Dutta, Radiative Transition in GaAs and Other III-V Compounds R. K. Ahrenkiel, Minority-Carrier Lifetime in III-V Semiconductors T. Furuta, High Field Minority Electron Transport in p-GaAs M. S. Lundstrom, Minority-Carrier Transport in III-V Semiconductors R. A. Abram, Effects of Heavy Doping and High Excitation on the Band Structure of GaAs D. Yevick and W. Bardyszewski, An Introduction to Non-Equilibrium Many-Body Analyses of Optical Processes in III-V Semiconductors... 

Figure 5.9 Effect on the band structure of doping silicon (i) with phosphorus (ii) and aluminium (Hi)...

---