EFFECT OF GAMMA
IRRADIATION AT ZNO
THIN FILM BY Cs-137
M. Tekin
a
, N. Baydoğan
b
, E.S. Kayalı
a
,
H. Çimenoğlu
a
, H. Sengel
c
, F. Akmaz
c
, A. Parlar
c
,
Istanbul Technical University
Institute of Energy, Nuclear Researches Division,
Metallurgical & Materials Engineering Department,
ZnO:Al thin films have been used widely in industrial
applications related to
electronic and optical
applications such as photoelectric devices, light
emitting diodes.
The physical and chemical properties of this film make
it a promising candidate for opto-electronic
applications.
This paper presents some data on the radiation damages with Cs-137 radioisotope. In this study, the response of Al-doped ZnO thin film to gamma radiation was investigated .
Gamma radiation caused to variations in optical properties of ZnO:Al thin films.
Al-doped ZnO thin film was prepared by the sol-gel spin coating method using homogeneous and stable zinc acetate-dihydrat, ethanol, diethanolamin sol and doped with 5 at. % Al with respect to Zn.
The gamma irradiation on the annealing temperature of the thin film was investigated for the different annealing temperatures.
The spin speed can effect the optical characteristics of the thin film. The changes on optical characteristics of irradiated ZnO:Al thin film.
The mechanisim of the thickness on the film is investigated in order to define the interaction of sol with the substrate.
EXPERIMENTS AND METHODS
a) Material Properties
Substrate : Soda-lime silicate glass
The thickness of substrate: 1 mm
Silica substrates were cleaned using methanol, acetone and deionized water and then dried in the air before the deposition of the films.
b)
Details on Sol-Gel Process
ZnO:Al thin films were deposited by a spin-coating process.
To obtain sol, Zincacetat-dihydrat was first dissolved into ethanol by adding Diethanolamin at 60 °C. The dopant source of aluminium was Aluminiumnitrat-Nanohydrat
The molar ratio of dopant (Al:Zn) was 5%.
The solution was dropped onto glass substrates at room temperature. The obtained solution was transparent.
c) Irradiation Process
Source Samples
Fig.1 The setlement of samples
Table-1 The properties of Cs-137 radioisotope
Irradiation was done at room temperature.
Radioisotope K R m2 / Ci h) A (Ci) T(y)1/2 E (keV) Abundance (%) Production Mode Cs-137 0.33 9.47 30.17 661.66 85.21 Fission
RESULTS AND DISCUSSIONS
1 2 3 4 5 6 L a y e r s 0 2 0 4 0 6 0 8 0 1 0 0 T h ic kn es s (n m ) 4 0 0 ( ° C ) 5 0 0 ( ° C )
The thickness of the film has changed with the increasing of the film layer.
This change was fitted to a polynomial function with degree 2. It is expected that the relation between the thickness and layer of the film should be fitted a linear function. However when the number of the layer of the film increases the surface of the film reaches more formless and rough structure at a topographical way. The friction between the sol and the substrate increases as the result of the increase of the thickness with the more formless and rough surface.
