Author :
Publisher :
ISBN 13 :
Total Pages : 5 pages
Book Rating : 4.:/5 (683 download)
Book Synopsis Identifying Electronic Properties Relevant to Improving Stability in A-Si by :
Download or read book Identifying Electronic Properties Relevant to Improving Stability in A-Si written by and published by . This book was released on 1998 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work carried out by the University of Oregon Under this subcontract focused on the characterization and evaluation of low-gap (a-Si, Ge:H) alloy materials and on issues related to overall stability in the mid-gap (a-SiH) materials. First, researchers characterized an extensive series of Uni-Solar a-Si, Ge:H samples using drive-level capacitance profiling and the analysis of sub-band-gap photocapacitance and photocurrent spectra. Thus, several bands of deep defect transitions were identified. Researchers were able to verify that charged defects are responsible for the different observed defect bands in device-quality a-Si, Ge:H alloy material. Second, they reported results of their measurements on a-Si, Ge:H alloy ''cathodic'' samples produced at Harvard University; these samples were found to exhibit significantly lower defect densities in the high Ge composition range (>50at.% Ge) than alloy samples produced either by conventional glow discharge of photo-chemical vapor deposition. Third, they performed voltage pulse stimulated capacitance transient measurements on a-Si:H/a-Si, Ge:H heterostructure samples to look for carrier trapping states that might be associated with this interface; they found there was a clear signature of trapped hole emission extending over long times associated specifically with the interface itself in concentrations of roughly 1011 cm−2. Fourth, researchers reported the results on several hot-wire a-Si:H samples produced with varying hydrogen levels. Their studies indicate that hot-wire-produced a-Si:H, with H levels between 2-5at.%, should lead to mid-gap devices with superior properties. Finally, they discussed some results on glow-discharge material, as well electron-cyclotron-resonance-deposited a-Si:H grown under hydrogen dilution conditions, and confirmed that, in terms of deep-defect creation, such films exhibited improved stability compared to conventional glow-discharge material.