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Vapour transport grown photosensitive GeO2 thin film
[Display omitted] •Growth of GeO2 TF by the vapour deposition technique.•Modified BAC and Urbach models are used to simulate band to band transitions.•The relative refractive index of GeO2 is theoretically calculated to be ∼ 1.8.•Negative temperature coefficient of resistance is due to oxygen relate...
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Published in: | Materials research bulletin 2021-10, Vol.142, p.111397, Article 111397 |
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Main Authors: | , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | [Display omitted]
•Growth of GeO2 TF by the vapour deposition technique.•Modified BAC and Urbach models are used to simulate band to band transitions.•The relative refractive index of GeO2 is theoretically calculated to be ∼ 1.8.•Negative temperature coefficient of resistance is due to oxygen related defects.•Wide temperature dependent stable photosensitivity of device is observed.
GeO2 thin film (TF) was fabricated by vapour deposition technique in a two zone horizontal quartz tube. Field emission-scanning electron microscopy showed the formation of 200 nm TF on the Si (100) substrate. The X-ray diffraction depicted the presence of the polycrystalline GeO2 TF. The UV–vis absorption spectrum showed humps at 3.1 eV, 4.0 eV and 5.4 eV. The band anticrossing (BAC) model is modified using the Urbach equation to understand the different transitions in the optical absorption spectrum. We have theoretically calculated the relative refractive index (r.i.) (nr) of the GeO2 as 1.8. The temperature dependent current (I)–voltage (V) characteristics and photocurrent of the Au/GeO2/p-Si Schottky device predicted the tunnelling of the carriers, presence of oxygen defects at the junction. The device’s temporal response indicated good photosensitivity at all temperatures and a significant increase in photocurrent was obtained as the temperature increased from 303 K to 403 K. |
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ISSN: | 0025-5408 1873-4227 |
DOI: | 10.1016/j.materresbull.2021.111397 |