UV-vis diffuse reflectance spectra showed that the absorption of TiO2-S-Fe in the visible light district was strengthened and the band edge moved to longer wavelength obviously.

All these characteristics depend not only on the relative position δ of the excited level ω _1 with respect to the band-edge ω _c but also on the photon density of states ρ(ω_k) (or the band-edge smoothing parameter ε ) near the band edge.

Both (10 11) and (11 20) peaks of the X ray diffraction (XRD) spectra and the relevant yellow luminescence (YL) of the photoluminescence (PL) spectrum as well as the impurity states close to the band edge were respectively observed upon lowing the N 2 flow rate.

The sulfated TiO\-2 (SO\+\{2-\}\-4/TiO\-2) possessed higher specific surface area, and the band gap of them increased and the band edge blue_shifted,thus yielding a larger redox potential and leading to the enhanced photocatalytic oxidation activity.

The resonator exhibited a very high Q value about 30000 at 77 K. The filter showed an excellent selectivity. At the band edge of the filter, the slope was about 17 dB/MHz.

In order to understand the band edge discontinuities at a-Si:H/c-Si interfaces, we also investigated the voltage- and temperature-dependent spectral response (SR) of solar cells with a fixed thickness (100 nm) of i-a-Si:H layer, and compared with the experimental results reported by S. Gall et al.

The spectral properties of nanocrystallines Dy 0.5 Sr 0.5 CoO 3- Y were studied. The results show that the band edge of emission spectra is blue shift when the size of particles decrease to nanometer.

Due to the low-frequency of applied field, the various transition pathways may interfere with each other and the band edge effect exists, Spontaneous emission can be suppressed significantly.

Absorption of Narrow-Gap HgCdTe Near the Band Edge Including Nonparabolicity and the Urbach Tail

The room-temperature photoluminescence (PL) of the as-deposited films has been shown that growing in the O2/Ar/H2 mixture ambient significantly increases the band edge emission while inhibiting the visible emission.

These calculations can be corrected for thermal excitation by adding a factor, m**, to the band edge calculation: m* = m** m*be, where m** was found empirically to be m** = 4.52 × 10-3T + 0.78.

The intensity of the band edge emission is comparable to that of the acceptor related emission for layers grown at 465°C.

GaBN alloys with about 7% substitutional boron were also produced by implantation of 5 × 1016 cm-2 B ions at 60 keV into GaN, as evidenced by the shift of the band edge emission in cathodoluminescence spectra from 3.4 eV for GaN to 3.85 eV for GaBN.

This paper introduces a direct display method for measuring MOS interface state density distribution. Instead of using the u-sual digital calculation, this method has recourse to analog circuit operations. Its measurement is based on high-frequency C-V and quasi-static C-V method. The effective measurement ranges from 1010 to 1013 V-1 cm-2. Compared with digital calculations, this method can achieve greater accuracy near the midgap; however, the error is comparatively great when it comes to the band edge....

This paper introduces a direct display method for measuring MOS interface state density distribution. Instead of using the u-sual digital calculation, this method has recourse to analog circuit operations. Its measurement is based on high-frequency C-V and quasi-static C-V method. The effective measurement ranges from 1010 to 1013 V-1 cm-2. Compared with digital calculations, this method can achieve greater accuracy near the midgap; however, the error is comparatively great when it comes to the band edge. By using this method, it takes only 20 minutes to make a Nss-ψs distributron curve of a MOS sample or to make comparisons between interface state density distributions of several M OS samples treated under different conditions.

A systematic investigation and numerical results of calculation of T2 symmetric deep level wave function induced by short range defect potential in Si are described, based on a recently developement on site defect potential Green's function method. [5,6] Such a complete information of T2 symmetric wave functions in Si is presented for the first time. The occupation probability P1 of the wave function located around four nearest neighbour sites of the defect center has a peak exceeding 50%. This part of wave...

A systematic investigation and numerical results of calculation of T2 symmetric deep level wave function induced by short range defect potential in Si are described, based on a recently developement on site defect potential Green's function method. [5,6] Such a complete information of T2 symmetric wave functions in Si is presented for the first time. The occupation probability P1 of the wave function located around four nearest neighbour sites of the defect center has a peak exceeding 50%. This part of wave function could be described by T2 symmetric combination of four hybrid orbital quasi dangling bonds located at four nearest neighbour sites and pointing toward the defect center. The total occupation probability of wave function located on the 0,1,2 shells arround the defect center is about 70%. The rest part of the wave function extends diversely over a wide range of space. The characteristics of the wave function are insensitive to the defect energy over most part of the energy range in the gap. Only when the defect energy level approaches very closely to the band edge of either conduction (Ec) or valence (Ev) band, the aforementioned peak P1 disappears and the wave function extends smoothly all over the space. A T2 symmetric deep level due to ideal vacancy is found at 0.51 eV up to the Ev .

The behavior of deep level wavefunctions induced by short range defect potential is investigated when the energy difference e between the defect state and the band edge is very small. When e→0, the wavefunctions tend to expand in real space and concentrate in k space when some symmetric matching condition is satisfied. A specific scheme is developed for efficient and reliable numerical calculations of the deep level wavefunctions when e is very small. For the case of A1 symmetric defect states near the...

The behavior of deep level wavefunctions induced by short range defect potential is investigated when the energy difference e between the defect state and the band edge is very small. When e→0, the wavefunctions tend to expand in real space and concentrate in k space when some symmetric matching condition is satisfied. A specific scheme is developed for efficient and reliable numerical calculations of the deep level wavefunctions when e is very small. For the case of A1 symmetric defect states near the bottom of the conduction band, for Si, when e <2 meV, the wavefunctions tend to concentrate rapidly in k space; for GaAs, the wavefunctio'ns do not concentrate in k space until e is as small as 0.1 meV. The critical e value corresponding to obvious concentration in k space is sensitive to the magnitude of the effective mass and the degree of matching of symmetry between the defect state and Bloch states at the band edge. For A1 defect states near the top of the valance band, no concentration in k space occur since the A1 defect states mismatch to the Block states at valance band maxima.