| Autor: |
Farid ul Islam, A.K.M.1, Islam, R.1, Khan, K.A.1 kakhan_ru@yahoo.ca, Yamamoto, Yoshiyuki2 |
| Předmět: |
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| Zdroj: |
Renewable Energy: An International Journal. Feb2007, Vol. 32 Issue 2, p235-247. 13p. |
| Abstrakt: |
Abstract: Spray deposited MnO2 thin films onto glass substrate were subjected to a post-deposition heat treatment and the effects of temperature on electrical transport properties were studied in details. The heating and cooling cycles of the samples are reversible after successive heat-treatments in air and vacuum. The films were polycrystalline in structure and the oxygen chemisorption–desorption process was found to play an important role in controlling the electronic properties. Various grain-boundary and energy band parameters were calculated by taking conventional extrinsic semiconductor theory and grain boundary trapping models into account. The samples were non-degenerate n-type semiconductors. The transport properties are interpreted in terms of Seto''s model which was proposed for polycrystalline semiconducting films. The inter-crystallite boundaries of the thin films play an important role in the transport properties. [Copyright &y& Elsevier] |
| Databáze: |
GreenFILE |
| Externí odkaz: |
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