Deposition of highly photoconductive wide band gap a-SiO:H thin films at a high temperature without H-dilution
| Autor: | Özcan Öktü, Alp Osman Kodolbaş, Akın Bacıoğlu |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Materials science
Renewable Energy Sustainability and the Environment Band gap Plasma-enhanced chemical vapor deposition Photoconductivity Dangling bond Analytical chemistry Chemical vapor deposition Thin film Fourier transform spectroscopy Surfaces Coatings and Films Electronic Optical and Magnetic Materials Amorphous solid |
| Zdroj: | Solar Energy Materials and Solar Cells. 89:49-59 |
| ISSN: | 0927-0248 |
| DOI: | 10.1016/j.solmat.2005.01.001 |
| Popis: | Electrical and optical characterisation of hydrogenated amorphous silicon–oxygen alloy thin films (a-SiO x :H, x 2 ) grown in a single chamber radio frequency plasma enhanced chemical vapour deposition (PECVD) system at a high substrate temperature of 300 °C is presented. The samples were investigated by Fourier transform infrared spectroscopy (FTIR), optical transmission, the constant photocurrent method (CPM), conductivity and steady-state photoconductivity measurements. With increasing oxygen concentration, the Tauc gap increases from 1.69 to 2.73 eV. The sample with an oxygen concentration of 26.2 at% and a reasonably high bandgap of 2.18 eV shows photoconductivity comparable to that of pure a-Si:H films. The Urbach parameter ( E 0 ) increases almost linearly with oxygen concentration whereas the dangling bond defect density is found to be saturating at a value of about 7.1×10 16 cm −3 . One of the highly alloyed samples with E 0 = 123 meV exhibited a detectable photosensitivity. |
| Databáze: | OpenAIRE |
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