Abstract
Oblique deposition and exposure to photons of energy greater than the bandgap have a marked effect on the structure and consequently on electrical and optical properties of amorphous chalcogenides. This paper presents a detailed study of photoinduced effect and oblique deposition effect on electrical and optical properties of a-GeSe2 films deposited at different angles (0°–80°). The indirect-optical bandgap energy (2.18 eV) was found to be independent of angle of incidence. The spectral response of refractive index and extinction coefficient has been determined in the wavelength range of 0.6–1 μm using the transmission spectra. Refractive index decreases with the increase in angle of incidence. The value of refractive index was observed to be 2.28 for 0° and 2.00 for 80° films at 0.646 μm. An increase in bandgap was also observed on exposure to the UV light for ∼120 min. The change in bandgap became more significant with the increase in angle of incidence (∼ 2.3% for 0° and ∼10.6% for 80°). The temperature dependence of conductivity along with time dependence and spectral response of photocurrent has also been investigated.
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Shimakawa K, Kolobov A, Elliot SR (1995) Adv Phys 44:475
KTanaka (1998) Phys Rev B 57:5163
Shimakawa K, oshida NY, Ganjoo A, Kuzukawa Y, Singh J (1998) Philos Mag Lett 77:153
Kuzukawa Y, Ganjoo A, Shimakawa K (1998) J Non-Cryst Solids 227–230:715
Macleod HA (1986) J Vac Sci Technol A4:418
Leamy HL, Gilmer GH, Dirks AG (1980) Curr Top Mater Sci 6:1
Manifacier JC, Gassiot J, Fillard JP (1976) J Phys E 9:1002
Swanepoel R (1983) J Phys E 16:1214
Swanepoel R (1984) J Phys E 17:896
Rajagopalan S, Harshvardhan KS, Malhotra LK, Chopra KL (1982) J Non- Cryst Solids 50:29
Pandaya DK, Rastogi AC, Chopra KL (1975) J Appl Phys 46:2966
Ke Tanaka (1990) Rev Solid St Sci 4:641
Kolobov AV, Oyanagi H, Tanaka K (1997) Phys Rev B 55:726
Shimakawa K, Yoshida N, Ganjoo A, Kuzukawa Y, Singh J (1998) Philos Mag Lett 77:153
Shimakawa K, Yoshida N, Ashtosh Ganjoo, Kuzukawa Y, Singh J (1998) Philos Mag Lett 77:153
Mott NF, Davis EA (1979) Electronic processes in non-crystalline solids, 2nd edn. Claredon Press, Oxford, p 272
Phillips JC (1981) J Non-Cryst Solids 43:37
Mott NF, Davis EA (1971) Electronic processes in non-crystalline materials. Oxford Claredon Press
Meyer W, Neldel H (1937) Zh Tekh Fiz 12:588
Roberts GG, Apsley N, Munn RW (1980) Phys Rev 60:61
Shimakawa K, et al (1991) J Non-Cryst Solids 137–138:1017
Biegelsen DK, Street RA (1980) Phys Rev Lett 44:803
Shimakawa K (1986) Phys Rev B 34:8703
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Bhardwaj, P., Shishodia, P.K. & Mehra, R.M. Optical and electrical properties of obliquely deposited a-GeSe2 films. J Mater Sci 42, 1196–1201 (2007). https://doi.org/10.1007/s10853-006-1456-y
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DOI: https://doi.org/10.1007/s10853-006-1456-y