CVV Auger line shapes in FeS2

We have measured the CVV Auger spectra of Fe and S from FeS2 and compared them, after deconvoluting, with results from other techniques and with band structure calculations. These Auger spectra exhibit a number of interesting features, including a strong feature similar to that found in metallic Fe, previously assigned to an 'autoionisation' process. The effective hole-hole interaction energy (Ueff) was calculated for each of the three Auger lines investigated. We found in each case that Ueff was less than twice the width of the valence band, so that these spectra could be considered as 'bandlike' and compared with the theoretical calculations of the density of states. The corrected Fe Auger spectra were compared with calculations made by Bullet [J Phys C15, 6163 (1982)] and were found to be in broad agreement

Auger line shape analysis of Zn3P2

The technique of Auger line shape analysis is applied to Zn3P2 single crystal. Zn3P2 is a semiconductor that has some potential as a material suitable for solar energy conversion. The measured line shapes are band-like and so are amenable to analysis and comparison with theory. The line shapes are recovered from the spectra by background subtraction followed by the Van Cittert deconvolution. This technique is first applied to the L3VV line of copper and the results checked against those already in the literature. The line shapes for Zn3P2 are compared with band structure calculations. In general, there is good agreement between the theory and our measured valence band structure

Auger and XPS study of band structure of zinc phosphide

The valence band region XPS spectrum of Zn3P2 has been compared to loss-deconvoluted LVV Auger lineshapes and the band structure calculation of Lin-Chung [Phys. Status Solidi (b) 47 (1971) 33]. Fair agreement has been found from these comparisons

Amorphous silicon solar cells

Thin films of hydrogenated amorphous silicon have been prepared by chemical vapour deposition at atmospheric pressure from a mixture of silanes over a heated substrate. This approach provides an alternative method to glow discharge and it has several substantial advantages, including safety and lower costs. High deposition rates have been obtained by use of a silent electrical discharge in the gas stream prior to the deposition process. Solar cells fabricated from these films show open circuit voltages of up to 400 mV but current densities are low. This is attributed to a low hydrogen content in the films. Physical and chemical characterization techniques have been used to identify the limiting factors in the performance of these devices. Further research is proposed to improve the efficiency of the photovoltaic devices

Enhancing osseointegration using surface-modified titanium implants

Osseointegrated dental implants are used to replace missing teeth. The success of implants is due to osseointegration or the direct contact of the implant surface and bone without a fibrous connective tissue interface. This review discusses the enhancement of osseointegration by means of anodized microporous titanium surfaces, functionally macroporous graded titanium coatings, nanoscale titanium surfaces, and different bioactive factors