SU Shi-chen, LV You-ming, ZHANG Ji-ying, SHEN De-zhen. Substrates Temperature Influence on the Structural and Opticcal Properties of ZnO Films[J]. Chinese Journal of Luminescence, 2011,32(7): 736-739
SU Shi-chen, LV You-ming, ZHANG Ji-ying, SHEN De-zhen. Substrates Temperature Influence on the Structural and Opticcal Properties of ZnO Films[J]. Chinese Journal of Luminescence, 2011,32(7): 736-739 DOI: 10.3788/fgxb20113207.0736.
Substrates Temperature Influence on the Structural and Opticcal Properties of ZnO Films
The ZnO films grown with different growth temperature have been deposited on
c
-Al
2
O
3
substrates by plasma assistant molecular beam epitaxy (P-MBE). Their crystal structures are characterized by X-ray diffraction (XRD). The XRD results indicate that all the ZnO films with the (002) preference orientation of hexagonal wurtzite structure. The full width at half maximum (FWHM) of the (002) diffraction peak decreases as the growth temperature increasing. The surface morphology of the ZnO films is measured by scanning electron microscope (SEM)
the surface morphology of the ZnO films grown at different growth temperature changes gradually. In the SEM image of the film grown at 500 ℃
there are a large number of particles
and the surface of the film is rough. The particle size is about 50~100 nm.The particle size increases (about 100~200 nm) at 600 ℃ growth
which indicates that the particle size increase with the increasing of the growth temperature. As the film growth temperature reaches 700 and 800 ℃
it can be found that the surface of the film become uniform and smooth from the SEM image. The photoluminescence (PL) intensity of the ZnO film increased with the increasing of the growth temperature. The origin of the PL peak is the free exciton emission. The carrier concentration and Hall mobility of the films as a function of growth temperature are studied. Hall measurements show that all the films are n-type. The carrier concentration value decreases gradually from 3.410
18
cm
-3
to a value of 1.810
18
cm
-3
with increasing the growth temperature from 500 to 800 ℃. The Hall mobility of ZnO films rises from 11 cm
2
/(Vs) to 51 cm
2
/(Vs) with the increase of film growth temperature. The high quality ZnO thin films was obtained at 800 ℃
exhibiting that the FWHM of XRD is about 0.05
the Hall mobility is about 51 cm
2
/(Vs)
the carrier concentration is about 1.810
18
cm
-3
.
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references
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