Donor states

Vos M H, Jones M R, Breton J, Lambry J-C and Martin J-L 1996 Vibrational dephasing of long- and short-lived primary donor states in mutant reaction centers ot Rhodobacter sphaeroides Biochemistry 35 2687-92... 

For H at T in Ge, Pickett et al. (1979) carried out empirical-pseudopotential supercell calculations. Their band structures showed a H-induced deep donor state more than 6 eV below the valence-band maximum in a non-self-consistent calculation. This binding energy was substantially reduced in a self-consistent calculation. However, lack of convergence and the use of empirical pseudopotentials cast doubt on the quantitative accuracy. More recent calculations (Denteneer et al., 1989b) using ab initio norm-conserving pseudopotentials have shown that H at T in Ge induces a level just below the valence-band maximum, very similar to the situation in Si. The arguments by Pickett et al. that a spin-polarized treatment would be essential (which would introduce a shift in the defect level of up to 0.5 Ry), have already been refuted in Section II.2.d. 

Tin oxide is a semiconductor with a wide band gap of Eg 3.7 eV, which can easily be doped with oxygen vacancies and chlorine acting as donor states. It is stable in aqueous solutions and hence a suitable material for n-type semiconducting electrodes. 

R. Czerw, M. Terrones, J.-C. Charlier, X. Blase, B. Foley, R. Kamalakaran, N. Grobert, H. Terrones, D. Tekleab, P. M. Ajayan, W. Blau, M. Ru2hle, D. L. Carroll, Identification of electron donor states in N-doped carbon nanotubes, Nano Lett., vol. 1, pp. 457-460, 2001. 

In the fluctuation band of electron energy of hydrated redox particles, the donor band of the reductant is an occupied band, and the acceptor band of the oxidant is a vacant band. The level erotsDcno at which the donor state density equals the acceptor state density (Aai/e) = Dox(e)) is called the Fermi level of the redox electron by analogy with the Fermi level e, of metal electrons [Gerischer, 1961]. From Eqns. 2—48 and 2—49 with f BED(e) =-DoxCe), we obtain the Fermi level Tiixxox.) (the redox electron level) as shown in Eqn. 2-51 ... 

The fact that the temperature domain of positive Seebeck coefficients below Ty, see Fig. 6, is wiped out by x = 0.01 shows that a donor state associated with an F ion lies above the top of the FeB-ai(J,) valence band in the low-temperature phase it charge compensates the holes in that band. This, in turn, means that the clusters of an F" ion... 

Hamiltonian term describing the interaction between the donor state D) and the bridge state B,)... 

The complexity of this example (Cu in GaAs) can be increased by supposing that a single-donor state is also possible, i.e., that one of the two (p+, p ) electrons can be excited by less than band-gap energy. Then the / = 0 state has one electron, and a degeneracy gAQ = 4 /3 l = 4. Similarly, gA1 = 4 /2 2 = 6, gA2 = 4, and gA3 = 1. The charge-balance equation must include these additional electrons available for distribution. Thus, Eq. (B28) becomes... 

The energy of the donor state described by the wave function Fl (q) is IA + n wd, where Id is the ionization energy of the donor (Fig. 6). The total energy of the system "the core of the donor + electron as has been noted above, is nu)d. Thus, the energy with which the electron leaves the donor is equal to ruod — (Id + n tod) and the coefficient ynn has the form... 

We have extended the technique of Relaxation Spectrum Analysis to cover the seven orders of magnitude of the experimentally available frequency range. This frequency range is required for a complete description of the equivalent circuit for our CdSe-polysulfide electrolyte cells. The fastest relaxing capacitive element is due to the fully ionized donor states. On the basis of their potential dependence exhibited in the cell data and their indicated absence in the preliminary measurements of the Au Schottky barriers on CdSe single crystals, the slower relaxing capacitive elements are tentatively associated with charge accumulation at the solid-liquid interface. 

In Figure 1.8(b) the spectroscopic consequences of the heating in various chemical potentials of oxygen can be seen directly. The reduction causes a donor state band to... 

One of the outstanding properties of these substances is the extreme tunability of the electronic states under high pressure. In many cases a red shift on the order of 2000 cm-1/GPa has been observed (Yersin and Riedl, 1995). In addition, an effective nonradiative energy transfer from the cyano donor complexes to the f elements has been observed. In the case of Eu[Au(CN)2]3-3H20 this process even totally quenches the otherwise very intense and broad emission from the [Au(CN)2] layers. However, because of the very strong red shift of the donor electronic states, it is possible to shift the donor states over different levels of the f element. Especially, resonant and nonresonant energy transfer conditions can be achieved to study the transfer mechanism. 

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