Effect of Gamma Irradiation on Electrical and Photoelectrical Properties of CdFeTe Thin Films

Yıl 2022, Sayı: 20, 115 - 119, 31.12.2022

Matanat Mehrabova Aybeniz Abdullayeva Niyazi Hasanov Nizami Huseynov

Öz

Cd1−xFexTe solid solutions (purity 99.999%) was used to obtain thin films by the Molecular Beam Condensation method in a vacuum of 10-4Pa at substrate temperature Tsub=670 K and source temperature Tsour=1100 K. The condensation rate was υ = 18-20Ả / s and film thickness was d = 2 μm.
The crystal structure and surface morphology of thin films were studied by XRD method on Bruker D8 Advance XRD and SEM scanning electron microscope on Carl Zeiss Sigma VP. VAC of Cd1−xFexTe, x=0.08 thin films and the effect of γ-irradiation on them were studied at T=300K temperature. VAX measurements were performed at Dγ ≤ 1kGy γ-irradiation doze. The observed dependence shows that when Cd1−xFexTe (x=0.08) thin films are irradiated with small doses, deep levels are formed in the forbidden zone, and these levels are occupied by a part of electrons, the remaining electrons participate in conduction and cause an increase in current. When samples are irradiated with a dose of Dγ = 500 Gy, decrease in conductivity are observed, which indicates an increase in the concentration of defects. At doses Dγ ≥ 1kGy, conductivity decreases, which explained by an increase in the concentration of defects and thus a violation of the crystal structure.
Illumination of semiconductors leads to optical filling of local levels, which differs significantly from that in the dark. The effect of γ-irradiation on the photoconductivity can be explained by the formation of various types of defects in them. Spectral characteristics of photoconductivity shows that spectral range covers the wavelength range λ = 400 nm-1500 nm. There is a broad band in the PC spectrum, the width of the forbidden zone calculated from the PC maximum (λ = 800 nm) Eg = 1.55 eV at T = 300 K. The effect of γ-irradiation on spectral characteristics shows that Cd1−xFexTe, x=0.08 thin films are sensitive to illumination and γ –irradiation.

Anahtar Kelimeler

Semimagnetic, Semiconductor, Thin film, γ-irradiation, VAX, Photoconductivity, XRD, SEM

Effect of Gamma Irradiation on Electrical and Photoelectrical Properties of CdFeTe Thin Films

Öz

Cd1−xFexTe solid solutions (purity 99.999%) was used to obtain thin films by the Molecular Beam Condensation method in a vacuum of 10-4Pa at substrate temperature Tsub=670 K and source temperature Tsour=1100 K. The condensation rate was υ = 18-20Ả / s and film thickness was d = 2 μm.
The crystal structure and surface morphology of thin films were studied by XRD method on Bruker D8 Advance XRD and SEM scanning electron microscope on Carl Zeiss Sigma VP.
VAC of Cd1−xFexTe, x=0.08 thin films and the effect of γ-irradiation on them were studied at T=300K temperature. VAX measurements were performed at Dγ ≤ 1kGy γ-irradiation doze. The observed dependence shows that when Cd1−xFexTe (x=0.08) thin films are irradiated with small doses, deep levels are formed in the forbidden zone, and these levels are occupied by a part of electrons, the remaining electrons participate in conduction and cause an increase in current. When samples are irradiated with a dose of Dγ = 500 Gy, decrease in conductivity are observed, which indicates an increase in the concentration of defects. At doses Dγ ≥ 1kGy, conductivity decreases, which explained by an increase in the concentration of defects and thus a violation of the crystal structure.
Illumination of semiconductors leads to optical filling of local levels, which differs significantly from that in the dark. The effect of γ-irradiation on the photoconductivity can be explained by the formation of various types of defects in them. Spectral characteristics of photoconductivity shows that spectral range covers the wavelength range λ = 400 nm-1500 nm. There is a broad band in the PC spectrum, the width of the forbidden zone calculated from the PC maximum (λ = 800 nm) Eg = 1.55 eV at T = 300 K. The effect of γ-irradiation on spectral characteristics shows that Cd1−xFexTe, x=0.08 thin films are sensitive to illumination and γ –irradiation.

Anahtar Kelimeler

Semimagnetic, Semiconductor, Thin film, γ-irradiation, VAX, Photoconductivity, XRD, SEM

Kaynakça

• [1] J. K. Furdyna, Diluted magnetic semiconductors: An interface of semiconductor physics and magnetism, Journal of Applied Physics - AIP Publishing, 1982, 53, 7637, doi.org/10.1063/1.330137
• [2] A. Mycielski, Fe‐based semimagnetic semiconductors, Journal of Applied Physics - AIP Publishing, 1988, 63, 3279, doi.org/10.1063/1.340813
• [3] A. Holda, A. Rodzik, A. A. Melnikov, P. Zhukowski. Allocation and Properties of Iron States in Cd1-xFexTe in Forbidden Gap Energy Range, Acta Phys.Polon., 1995, 87, 357, doi.10.12693/APhysPolA.87.357
• [4] P. Zhukovskii, Ya. Partyka, P. Vengerek, T. Koltunovich, Yu. Sidorenko, V. Stelmakh, N. Lapchuk. The alternating current conductivity and electron spin resonance Cd1−xFexTe compounds. Semiconductors, 2007, 41, 5, 544-548.
• [5] P. Zukowski, J. Partyka, P. We ˙ ¸gierek, J.W. Sidorenko, J. Szostak, A. Rodzik. Dielectric properties of Cd1−xFexTe semiconductor compounds. Semiconductors, 1999, 33, 3, 270-272.
• [6] S.A. Permogorov, T.P. Surkova, L.N. Tenishev. Exciton luminescence of Cd1−xFexTe solid solutions. Physics of the Solid State, 1998, 40, 5, 897-899
• [7] M. A.Mehrabova, N.H.Hasanov, N.I.Huseynov, A.I.Kazimova, Ab initio calculations of defects in Cd1-xMnxTe(Se) semimagnetic semiconductors, Journal of Radiation Researches, 2020, 7, 2, 39 – 42
• [8] Mehrabova M.A., Defect formation energy, impact of ionizing radiation on physical properties of II-IV groups’ chalcogenides. Journal of Radiation Research, 2017, 4, 1, 43 – 56
• [9] M.A.Mehrabova, H.R.Nuriyev, H.S.Orujov, A.M.Nazarov, R.M.Sadigov, V.N.Poladova. Defect formation energy for charge states and electrophysical properties of CdMnTe, Proc. SPIE Photonics, Devices and Systems VI, SPİE, 2015, 9450, 945001 – 9450010
• [10] M.A.Mehrabova, H.S.Orujov, N.H.Hasanov. Ab initio study of defects in CdMnTe: Electronic structure and related properties. International Journal of Materials Science and Applications, Science PG, 2014, 3, 6-1, 24 – 32
• [11] Mehrabova M.A., Nuriyev H.R., Orujov H.S., Hasanov N.H., Abdullayeva A.A., Suleymanov Z.I. Ab-initio calculations of electronic structure of CdFeTe and optical properties. Conference proceedings Modern Trends in Physics. Baku, 01-03 May 2019, 39-42
• [12] Mehrabova M.A., Nuriyev H.R., Orujov H.S., Hasanov N.H., Abdullayeva A.A., Nazarov A.M., Huseynov N.I., Gulmammadov K.D., Asadov F.G. First-principles study of defects in CdMn(Fe)Te. Effect of γ-irradiation on optical properties of CdMn(Fe)Te epitaxial films. 7th Rostocker International Conference “Thermophysical Properties to Technical Thermodynamics” (Thermam 2018), Almaniya, Rostok, 26th – 27th July 2018, 45
• [13] Мehrabova М.А., Nuriyev H.R., Оrujov H.S., Hasanov N.H., Кеrimova.Т.I., Аbdullayeva.А.А., Kazimova.A.I. Effect of gamma irradiation on conductivity of Cd1−xFexTe. Semiconductors, 2020, 61, 12, 2306-2309