Photo-induced enhancement of the dark conductivity in nanocrystalline germanium/amorphous silicon composite thin films
| Autor: | J. K. Nangoi, James Kakalios, K. Bodurtha |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Amorphous silicon
Materials science genetic structures Composite number Analytical chemistry General Physics and Astronomy chemistry.chemical_element Germanium 02 engineering and technology Conductivity 021001 nanoscience & nanotechnology 01 natural sciences Nanocrystalline material chemistry.chemical_compound chemistry Plasma-enhanced chemical vapor deposition 0103 physical sciences Charge carrier 010306 general physics 0210 nano-technology Quantum tunnelling |
| Zdroj: | Journal of Applied Physics. 124:165102 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.5031434 |
| Popis: | A light-induced increase in the dark conductivity is observed in composite thin films consisting of hydrogenated amorphous silicon (a-Si:H) containing nanocrystalline germanium (nc-Ge) inclusions, synthesized by co-deposition in a dual-chamber plasma enhanced chemical vapor deposition system. Unlike the Staebler-Wronski effect or persistent photoconductivity observed in amorphous semiconductors, this photo-induced excess conductivity is observed even in composite nc-Ge/a-Si:H films with a minimal photosensitivity. The decay of the excess conductivity follows a single-exponential time dependence, with a temperature independent time constant. We propose that spatial separation of photo-excited charge carriers by the compositional morphology present in the film, with tunneling of photo-excited holes into the germanium nanocrystalline inclusions, is involved in the creation and removal of this effect. |
| Databáze: | OpenAIRE |
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