Vacuum evaporated thin films of Zinc Telluride (ZnTe) of 5000 Å thickness have been deposited on glass substrates at different substrate temperatures (303 K, 373 K, 448 K). Structural parameters were obtained using XRD analysis. Atomic Force Microscope (AFM) in non-contact mode has been used to study the surface morphological properties of the deposited thin films. The results obtained from structural and surface morphological studies have been correlated and it is found that the films deposited at higher substrate temperatures possess increasingly good crystallinity and smoother surfaces.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/930

Gandhi, J.R.

Hingarajiya, K.S.

Panchal, C.J.

Patel, K.D.

Solanki, G.K.

SocioEconomic Challenges Journal (Sumy State University)

 
 
 
J. Nano- Electron. Phys. 
3 (2011) No1, P.41-46 
? 2011 SumDU 
(Sumy State University) 
 
 
41 
PACS numbers: 68.55 aj, 73.90 + F 
 
EFFECT OF SUBSTRATE TEMPERATURE ON STRUCTURAL AND 
MORPHOLOGICAL PARAMETERS OF ZnTe THIN FILMS 
 
K.D. Patel1, G.K. Solanki1, C.J. Panchal2, K.S. Hingarajiya1, J.R. Gandhi1 
 
1 Department of Physics, Sardar Patel University 
 Vallabh Vidyanagar, 388 120, Gujarat, India 
 E-mail: kdptflspu@yahoo.com 
2 Faculty of Technology, Applied Physics Department,  
 M.S. University of Baroda, Vadodara 390001, Gujarat, India 
 
Vacuum evaporated thin films of Zinc Telluride (ZnTe) of 5000 ? thickness  have  
been deposited on glass substrates at different substrate temperatures (303 K, 373 K, 
448 K). Structural parameters were obtained using XRD analysis. Atomic Force 
Microscope  (AFM)  in  non-contact  mode  has  been  used  to  study  the  surface  
morphological properties of the deposited thin films. The results obtained from 
structural and surface morphological studies have been correlated and it is found that 
the films deposited at higher substrate temperatures possess increasingly good 
crystallinity and smoother surfaces. 
 
Keywords: ZNTE  THIN  FILM,  THERMAL  EVAPORATION,  XRD,  AFM,  SUB-
STRATE TEMPERATURE. 
 
(Received 04 February 2011, in final form 17 March 2011) 
 
1. INTRODUCTION 
 
Thin films of II-VI compound semiconductors have drawn researcher’s 
attention for more than four decades. ZnTe is expected to be a promising 
material for a variety of optoelectronic devices, such as pure green light 
emitting devices, detectors for various optoelectronic instrumentation, etc. 
because  of  its  direct  wide  band  gap  of  2.26  eV  [1-3].  It  is  also  used  as  
terahertz detectors [4, 5] and window material for CdTe based solar cells [6].  
Many researchers have used various techniques for the fabrication of ZnTe 
thin films including Metal organic chemical vapor deposition [7], MBE [8], 
vacuum evaporation [9-11] R.F. Sputtering [12] and Electrodeposition [13-
17]. Among these, thermal evaporation technique offers several advantages 
including simplicity and cost effectiveness for larger area processing. In this 
paper  we  report  our  results  of  our  investigations  on  structural  and  
morphological properties dependence on substrate temperature in case of 
ZnTe thin films deposited using thermal evaporation technique.  
 
2. EXPERIMENTAL 
 
Thin films of ZnTe were deposited on an ultrasonically cleaned glass 
substrates using thermal evaporation technique, under a vacuum of  
10 – 6 Torr at different substrate temperatures (303 K, 373 K and 448 K). A 
polycrystalline ZnTe (99.999 %, Aldrich make) powder was used to deposit 
5000 ? thick films at the deposition rate of 5 ? per second. Structural 
analysis was made using X-ray diffraction technique (XRD) with the help of 
 
 
 
 EFFECT OF SUBSTRATE TEMPERATURE ON... 42 
 
CuK? radiation and the surface morphological study was carried out using 
atomic force microscope in non-contact mode with tungsten carbide tip. 
 
3. RESULTS AND DISCUSSION 
 
3.1 Structural Analysis 
 
The X-ray diffractograms of the thin films deposited at various substrate 
temperatures are shown in Fig. 1. It is observed that XRD patterns of all 
three films show a most preferred orientation along (111) plane. Also the 
most  prominent peak is  observed nearly at  25.6? for  2?, which shows that 
the deposited films possess cubic structure [18]. Structural parameters of 
the deposited films are given in Table 1. The sharper and intense peaks, in 
Fig. 1, for films deposited at increased substrate temperatures exhibit an 
improved crystalline structure of the films. Particle size values also 
increases with increase in the substrate temperature. 
 
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
55000
60000
65000
70000
20 25 30 35
Li
n 
(C
ou
nt
s)
Ts = 448 K
Ts = 373 K
Ts = 303 K
2?
Li
n 
(C
ou
nt
s)
 
 
Fig. 1 – XRD peaks of ZnTe thin films of thickness 5000 ?, deposited at various 
substrate temperatures 
 
Table 1 – Structural parameters of ZnTe thin films of thickness 5000 ? 
deposited at various substrate temperatures 
 
Parameter Ts ? 303 K Ts ? 373 K Ts ? 448 K JCPDS  Values 
a ? b ? c (?) 6.0038 6.0183 6.0414 6.0700 
Unit Cell Volume 
V (?)3 216.4106 217.9844 220.5021 223.6485 
X-ray Density 
? (gm ? cm3) 5.9221 5.8794 5.8123 5.7306 
 
3.2 Morphological Analysis 
 
The surface morphology of ZnTe films have been studied using Atomic Force 
Microscopy. Two dimensional and three dimensional AFM images (5 µm ? 
5 µm) of the deposited films along with height profile and the power 
spectrum are shown in Fig. 2. 
 
 
 
43 K.D. PATEL, G.K. SOLANKI, C.J. PANCHAL, ET AL.  
 
 
 
 
 
 
 
Fig. 2 – Two and three dimensional images of ZnTe Thin films of Thickness 5000 ?, 
deposited at various substrate temperatures: Ts ? 303 K  (a),  Ts ? 373 K (b), 
Ts ? 448 K (c) 
 
The data obtained from the analysis are given in Table 2. The difference 
between the rms and average roughness values of line-1 and line-2 
(12.87 nm & 24.72 nm) of the film at substrate temperature 303 K is larger 
than that of the other three lines. This indicates poor smoothness of the 
film in that area which can be clearly seen in the Fig. 2. In case of the films 
at  substrate  temperatures  373  K  and  448  K  this  difference  is  comparably  
smaller and is decreases with an increase in substrate temperature, which is 
the indication of better surface smoothness for the deposited films. 
 
 
 
 
 EFFECT OF SUBSTRATE TEMPERATURE ON... 44 
 
 
 a b c 
 
Fig. 3 – Histograms of ZnTe thin films of thickness 5000 ?, deposited at various 
substrate temperatures: Ts ? 303 K (a), Ts ? 373 K (b), Ts ? 448 K (c) 
 
 
Table 2 – Data obtained from AFM analysis of ZnTe thin films  
 
 
 
 A difference between peak and valley values (RP-V), obtained from the 
height profile is listed in Table 2. A large difference in the value of RP-V for 
all five lines of the image of film at lower substrate temperature (ranging 
from 44.15 nm to 210.7 nm) shows a poor surface smoothness of that film. 
The films deposited at higher substrate temperature show relatively low 
value of RP-V. Thus it is again confirmed by the difference of peak and 
valley observations made along five arbitrarily scanned horizontal lines of 
AFM scan that as substrate temperature increases, the surface smoothness 
improves.  
- 7.45410.9810.4114.655.02513.2013.132.5853.27118.44448
- 12.2526.9417.1027.715.93020.2524.007.6009.16139.18373
- 21.1742.8859.2078.495.15072.9173.0911.9714.8164.0530305
- 7.9139.67610.3614.855.03913.1513.062.5403.15117.59448
- 18.7930.0915.0428.695.93522.4424.018.40410.2748.89373
- 20.94223.2161.8780.125.15673.1573.119.19310.7444.1530304
- 4.6656.49511.1214.275.02012.8213.121.9092.38711.16448
- 19.0026.7313.5929.365.99722.9323.988.84610.6145.73373
- 59.92150.819.04113.95.15030.4573.1461.2668.35210.730303
- 6.36614.629.7714.015.03212.0713.103.1264.20120.99448
- 17.6926.3414.1929.236.10123.2923.998.47410.3144.03373
- 42.43164.437.4873.215.07647.4373.1239.2153.39206.830302
- 6.8919.97010.1315.045.03212.9213.142.8653.48216.86448
- 17.3132.6613.5928.516.06921.4823.999.55811.5249.98373
- 14.79109.961.2771.215.04966.6173.1512.8724.72124.730301
Valley 
R V (nm) 
Peak 
R P ( nm) 
Bearing 
Ratio 
@80%
(nm) 
Bearing 
Ratio 
@30%
(nm) 
Arc 
Lth 
( µ m) 
Med. 
Ht 
(nm) 
Mean 
Ht. 
(nm) 
R AVG 
(nm) 
R RMS 
(nm) 
R P- V 
(nm) 
Sub. 
Tem. 
(k) 
Line 
 
 
 
45 K.D. PATEL, G.K. SOLANKI, C.J. PANCHAL, ET AL.  
 
 Bearing ratio is the two dimensional projection of three dimensional 
surface. It gives a percentage of covered area in a film at the particular 
height.  Thus  it  shows  a  length  of  the  particle  above  a  horizontal  line  
throughout the distribution. Bearing ratio allows a comparison of roughness 
data for all three films and it is listed in Table 2. There is a large difference 
in these values (ranging from 71.21 nm to 113.9 nm @ 30%) and 19.04 nm 
to 61.87 nm @ 80 %) for the film deposited at Ts???303 K. For other two 
films with Ts???373 K and 448 K these differences are comparably smaller.  
 Power  spectrum  curve  is  the  important  parameter  in  analysis  of  any  
rough surface. It determines the contact area between two solids and can 
provide both, lateral and longitudinal information. A convenient way to 
describe surface roughness is to represent it in the term of profile heights 
z(x, y).  For  a  typical  digitized  AFM  scans,  the  value  of  x and y are 
quantized. Thus the power spectra exhibit the overall surface features of the 
deposited films as shown in Fig. 2. Looking to all three curves it is clear 
that the curve for the film at Ts???303 K possess an irregular and spread 
peaks  in  comparison  to  that  of  the  other  two  films.  Peaks  in  the  power  
spectrum indicate the periodicity of the surface and frequency of each peak 
gives a length that defines this periodic surface. Spread peak exhibits the 
deviations from average value. The spectrum for the film at Ts???373 K 
exhibits a sharp peak showing better surface properties. 
 Mean height, which is the central value of the roughness profile over the 
evaluation length, decreases as the substrate temperature of the deposited 
film is increased, showing a better smoothness of the film surface. The 
median height which is a mid point on the roughness profile over the 
evaluation length such that half of the data fall above it and half below it, 
is also inversely proportional to the substrate temperature of the film. In 
the obtained data, there is a large variations in median value for the film at 
Ts???303 K, particularly at line number 2 and 3, which can also be seen from 
the Fig. 3. The large difference in mean and median values of the film 
deposited at Ts???303 K shows an asymmetric distribution. 
 The  histogram  is  a  continuous  bar  diagram  in  which,  each  column  
represents the number of image pixels having the height value in a 
particular range. The histograms for the deposited films are shown in 
Fig. 2. It indicates a decrease in height from 51.2 nm to 14.8 nm for the 
films deposited at Ts???303 K to 448 K. 
 
4. CONCLUSION 
 
ZnTe thin films were successfully deposited on the glass substrates using 
thermal evaporation method at various substrate temperatures. It is clear 
from  structural  data  that  films  show  better  crystalline  structure  at  the  
higher substrate  temperature.  It  is  also  clear  from the detailed analysis  of  
various AFM parameters like rms and average roughness, mean and median 
heights, bearing ratio, peak and valley values, power spectrum density and 
histograms, that at the higher substrate temperatures the deposited films 
possesses a better smoothness and crystalline structure on its surface, which 
supports the XRD analysis. 
 
 
 
 
 EFFECT OF SUBSTRATE TEMPERATURE ON... 46 
 
 The  authors  are  thankful  to  Department  of  Chemistry,  Sardar  Patel  
University, Vallabh Vidyanagar and SICART, Vallabh Vidyanagar for AFM 
characterization and XRD analysis. 
 
REFERENCES 
1. D. Kurbatov, V. Kosyak, M. Kolesnyk, A. Opanasyuk and S. Danilchenko, 
Integrated Electronics 103, 32 (2008). 
2. R. Bhargava, Properties of wide band gap II-VI semiconsuctors- London, United 
Kingdom: INSPEC, The Institution of Electrical Engineers, 238 (1997). 
3. T. Tanaka, K. Saito, M. Nishio, Q. Guo and H. Ogawa, J. Mater. Sci. Mater. 
Electron. 20, 505 (2008). 
4. T. Ishizaki, N. Saito, O. Takai, S. Asakuru, K. Goto and A. Fuwa, Electrochim. 
Acta 50, 3509 (2005). 
5. C. Winnewisser, P.U. Japsen, M. Schall, V. Schiyja. H. Helm, Appl. Phys. Lett. 
70, 3069 (1997). 
6. P.V.S. Meyers, Proceedings of seventh Commission European Communities 
Confrrence o Photovolatic Solar Energy, Redial, Dordrecht, 1121, (1986) 
7. K. Wolf, H. Stanzl, A. Naumov, H.P. Wagnor, W. Kuhn, B. Kahn, W. Gebhardt, 
J. Cryst. Growth 138, 412 (1994). 
8. R.L. Gunshor, L.A. Kolodziejski, N. Otsuka, S. Datta, Surf. Sci. 174, 522 (1986). 
9. U. Pal, S. Saha, A. K. Chaudhari, V.V. Rao, H.D. Benarji, J. Phys. D: Appl. Phys. 
22, 965 (1989). 
10. R. Sarma, N. Mazumdar and H.L. Das, Bull. Mater. Sci. 29, 11 (2006). 
11. G.I. Rusu, P. Prepilita, N. Apetroaei and G. Popa, J. Optoelectron. Adv. M. 7(2), 
829 (2005). 
12. H. Belakhder, A. Outzourhit, E.L. Ameziane, Thin Solid Films 382, 30 (2001). 
13. M. Neumann-Spallart, C. Konigstein, Thin Solid Films 265, 33 (1995). 
14. A.B. Kashyout, A.S. Arico, P.L. Antonucci, F.A. Mohamed, V. Antonucci, 
Mater. Chem. Phys. 51, 130 (1997). 
15. K.K. Mishra, K. Rajeshwar, J. Electroanal. Chem. 273, 169 (1989). 
16. M.C. Lin, P.Y. Chen, I.W. Sun, J. Electrochem. Society 149, 653 (2001). 
17. B. Bozzini, M.A. Baker, P.L. Cavallotti, E. Cerri, C. Lenardi, Thin Solid Films 
388, 361 (2000). 
18. S. Venkatachalam, D. Mangalaraj, Sa.K. Narayandass, K. Kim, J. Yi, Physica B 
358, 27 (2005). 


English

Effect of substrate temperature on structural and morphological parameters of ZnTe thin films

Electronic Sumy State University Institutional Repository

   J. Nano- Electron. Phys. 3 (2011) No1, P.41-46  2011 SumDU (Sumy State University)   41 PACS numbers: 68.55 aj, 73.90 + F  EFFECT OF SUBSTRATE TEMPERATURE ON STRUCTURAL AND MORPHOLOGICAL PARAMETERS OF ZnTe THIN FILMS  K.D. Patel1, G.K. Solanki1, C.J. Panchal2, K.S. Hingarajiya1, J.R. Gandhi1  1 Department of Physics, Sardar Patel University  Vallabh Vidyanagar, 388 120, Gujarat, India  E-mail: kdptflspu@yahoo.com 2 Faculty of Technology, Applied Physics Department,   M.S. University of Baroda, Vadodara 390001, Gujarat, India  Vacuum evaporated thin films of Zinc Telluride (ZnTe) of 5000 ' thickness  have  been deposited on glass substrates at different substrate temperatures (303 K, 373 K, 448 K). Structural parameters were obtained using XRD analysis. Atomic Force Microscope  (AFM)  in  non-contact  mode  has  been  used  to  study  the  surface  morphological properties of the deposited thin films. The results obtained from structural and surface morphological studies have been correlated and it is found that the films deposited at higher substrate temperatures possess increasingly good crystallinity and smoother surfaces.  Keywords: ZNTE  THIN  FILM,  THERMAL  EVAPORATION,  XRD,  AFM,  SUB-STRATE TEMPERATURE.  (Received 04 February 2011, in final form 17 March 2011)  1. INTRODUCTION  Thin films of II-VI compound semiconductors have drawn researcher’s attention for more than four decades. ZnTe is expected to be a promising material for a variety of optoelectronic devices, such as pure green light emitting devices, detectors for various optoelectronic instrumentation, etc. because  of  its  direct  wide  band  gap  of  2.26  eV  [1-3].  It  is  also  used  as  terahertz detectors [4, 5] and window material for CdTe based solar cells [6].  Many researchers have used various techniques for the fabrication of ZnTe thin films including Metal organic chemical vapor deposition [7], MBE [8], vacuum evaporation [9-11] R.F. Sputtering [12] and Electrodeposition [13-17]. Among these, thermal evaporation technique offers several advantages including simplicity and cost effectiveness for larger area processing. In this paper  we  report  our  results  of  our  investigations  on  structural  and  morphological properties dependence on substrate temperature in case of ZnTe thin films deposited using thermal evaporation technique.   2. EXPERIMENTAL  Thin films of ZnTe were deposited on an ultrasonically cleaned glass substrates using thermal evaporation technique, under a vacuum of  10 – 6 Torr at different substrate temperatures (303 K, 373 K and 448 K). A polycrystalline ZnTe (99.999 %, Aldrich make) powder was used to deposit 5000 ' thick films at the deposition rate of 5 ' per second. Structural analysis was made using X-ray diffraction technique (XRD) with the help of     EFFECT OF SUBSTRATE TEMPERATURE ON... 42  CuKD radiation and the surface morphological study was carried out using atomic force microscope in non-contact mode with tungsten carbide tip.  3. RESULTS AND DISCUSSION  3.1 Structural Analysis  The X-ray diffractograms of the thin films deposited at various substrate temperatures are shown in Fig. 1. It is observed that XRD patterns of all three films show a most preferred orientation along (111) plane. Also the most  prominent peak is  observed nearly at  25.6q for  2T, which shows that the deposited films possess cubic structure [18]. Structural parameters of the deposited films are given in Table 1. The sharper and intense peaks, in Fig. 1, for films deposited at increased substrate temperatures exhibit an improved crystalline structure of the films. Particle size values also increases with increase in the substrate temperature.  050001000015000200002500030000350004000045000500005500060000650007000020 25 30 35Lin (Counts)Ts = 448 KTs = 373 KTs = 303 K2TLin (Counts)  Fig. 1 – XRD peaks of ZnTe thin films of thickness 5000 ', deposited at various substrate temperatures  Table 1 – Structural parameters of ZnTe thin films of thickness 5000 ' deposited at various substrate temperatures  Parameter Ts   303 K Ts   373 K Ts   448 K JCPDS  Values a   b   c (') 6.0038 6.0183 6.0414 6.0700 Unit Cell Volume V (')3 216.4106 217.9844 220.5021 223.6485 X-ray Density U (gm u cm3) 5.9221 5.8794 5.8123 5.7306  3.2 Morphological Analysis  The surface morphology of ZnTe films have been studied using Atomic Force Microscopy. Two dimensional and three dimensional AFM images (5 µm u 5 µm) of the deposited films along with height profile and the power spectrum are shown in Fig. 2.    43 K.D. PATEL, G.K. SOLANKI, C.J. PANCHAL, ET AL.         Fig. 2 – Two and three dimensional images of ZnTe Thin films of Thickness 5000 ', deposited at various substrate temperatures: Ts   303 K  (a),  Ts   373 K (b), Ts   448 K (c)  The data obtained from the analysis are given in Table 2. The difference between the rms and average roughness values of line-1 and line-2 (12.87 nm & 24.72 nm) of the film at substrate temperature 303 K is larger than that of the other three lines. This indicates poor smoothness of the film in that area which can be clearly seen in the Fig. 2. In case of the films at  substrate  temperatures  373  K  and  448  K  this  difference  is  comparably  smaller and is decreases with an increase in substrate temperature, which is the indication of better surface smoothness for the deposited films.      EFFECT OF SUBSTRATE TEMPERATURE ON... 44    a b c  Fig. 3 – Histograms of ZnTe thin films of thickness 5000 ', deposited at various substrate temperatures: Ts   303 K (a), Ts   373 K (b), Ts   448 K (c)   Table 2 – Data obtained from AFM analysis of ZnTe thin films      A difference between peak and valley values (RP-V), obtained from the height profile is listed in Table 2. A large difference in the value of RP-V for all five lines of the image of film at lower substrate temperature (ranging from 44.15 nm to 210.7 nm) shows a poor surface smoothness of that film. The films deposited at higher substrate temperature show relatively low value of RP-V. Thus it is again confirmed by the difference of peak and valley observations made along five arbitrarily scanned horizontal lines of AFM scan that as substrate temperature increases, the surface smoothness improves.  - 7.45410.9810.4114.655.02513.2013.132.5853.27118.44448- 12.2526.9417.1027.715.93020.2524.007.6009.16139.18373- 21.1742.8859.2078.495.15072.9173.0911.9714.8164.0530305- 7.9139.67610.3614.855.03913.1513.062.5403.15117.59448- 18.7930.0915.0428.695.93522.4424.018.40410.2748.89373- 20.94223.2161.8780.125.15673.1573.119.19310.7444.1530304- 4.6656.49511.1214.275.02012.8213.121.9092.38711.16448- 19.0026.7313.5929.365.99722.9323.988.84610.6145.73373- 59.92150.819.04113.95.15030.4573.1461.2668.35210.730303- 6.36614.629.7714.015.03212.0713.103.1264.20120.99448- 17.6926.3414.1929.236.10123.2923.998.47410.3144.03373- 42.43164.437.4873.215.07647.4373.1239.2153.39206.830302- 6.8919.97010.1315.045.03212.9213.142.8653.48216.86448- 17.3132.6613.5928.516.06921.4823.999.55811.5249.98373- 14.79109.961.2771.215.04966.6173.1512.8724.72124.730301Valley R V (nm) Peak R P ( nm) Bearing Ratio @80%(nm) Bearing Ratio @30%(nm) Arc Lth ( µ m) Med. Ht (nm) Mean Ht. (nm) R AVG (nm) R RMS (nm) R P- V (nm) Sub. Tem. (k) Line    45 K.D. PATEL, G.K. SOLANKI, C.J. PANCHAL, ET AL.    Bearing ratio is the two dimensional projection of three dimensional surface. It gives a percentage of covered area in a film at the particular height.  Thus  it  shows  a  length  of  the  particle  above  a  horizontal  line  throughout the distribution. Bearing ratio allows a comparison of roughness data for all three films and it is listed in Table 2. There is a large difference in these values (ranging from 71.21 nm to 113.9 nm @ 30%) and 19.04 nm to 61.87 nm @ 80 %) for the film deposited at Ts 303 K. For other two films with Ts 373 K and 448 K these differences are comparably smaller.   Power  spectrum  curve  is  the  important  parameter  in  analysis  of  any  rough surface. It determines the contact area between two solids and can provide both, lateral and longitudinal information. A convenient way to describe surface roughness is to represent it in the term of profile heights z(x, y).  For  a  typical  digitized  AFM  scans,  the  value  of  x and y are quantized. Thus the power spectra exhibit the overall surface features of the deposited films as shown in Fig. 2. Looking to all three curves it is clear that the curve for the film at Ts 303 K possess an irregular and spread peaks  in  comparison  to  that  of  the  other  two  films.  Peaks  in  the  power  spectrum indicate the periodicity of the surface and frequency of each peak gives a length that defines this periodic surface. Spread peak exhibits the deviations from average value. The spectrum for the film at Ts 373 K exhibits a sharp peak showing better surface properties.  Mean height, which is the central value of the roughness profile over the evaluation length, decreases as the substrate temperature of the deposited film is increased, showing a better smoothness of the film surface. The median height which is a mid point on the roughness profile over the evaluation length such that half of the data fall above it and half below it, is also inversely proportional to the substrate temperature of the film. In the obtained data, there is a large variations in median value for the film at Ts 303 K, particularly at line number 2 and 3, which can also be seen from the Fig. 3. The large difference in mean and median values of the film deposited at Ts 303 K shows an asymmetric distribution.  The  histogram  is  a  continuous  bar  diagram  in  which,  each  column  represents the number of image pixels having the height value in a particular range. The histograms for the deposited films are shown in Fig. 2. It indicates a decrease in height from 51.2 nm to 14.8 nm for the films deposited at Ts 303 K to 448 K.  4. CONCLUSION  ZnTe thin films were successfully deposited on the glass substrates using thermal evaporation method at various substrate temperatures. It is clear from  structural  data  that  films  show  better  crystalline  structure  at  the  higher substrate  temperature.  It  is  also  clear  from the detailed analysis  of  various AFM parameters like rms and average roughness, mean and median heights, bearing ratio, peak and valley values, power spectrum density and histograms, that at the higher substrate temperatures the deposited films possesses a better smoothness and crystalline structure on its surface, which supports the XRD analysis.      EFFECT OF SUBSTRATE TEMPERATURE ON... 46   The  authors  are  thankful  to  Department  of  Chemistry,  Sardar  Patel  University, Vallabh Vidyanagar and SICART, Vallabh Vidyanagar for AFM characterization and XRD analysis.  REFERENCES 1. D. Kurbatov, V. Kosyak, M. Kolesnyk, A. Opanasyuk and S. Danilchenko, Integrated Electronics 103, 32 (2008). 2. R. Bhargava, Properties of wide band gap II-VI semiconsuctors- London, United Kingdom: INSPEC, The Institution of Electrical Engineers, 238 (1997). 3. T. Tanaka, K. Saito, M. Nishio, Q. Guo and H. Ogawa, J. Mater. Sci. Mater. Electron. 20, 505 (2008). 4. T. Ishizaki, N. Saito, O. Takai, S. Asakuru, K. Goto and A. Fuwa, Electrochim. Acta 50, 3509 (2005). 5. C. Winnewisser, P.U. Japsen, M. Schall, V. Schiyja. H. Helm, Appl. Phys. Lett. 70, 3069 (1997). 6. P.V.S. Meyers, Proceedings of seventh Commission European Communities Confrrence o Photovolatic Solar Energy, Redial, Dordrecht, 1121, (1986) 7. K. Wolf, H. Stanzl, A. Naumov, H.P. Wagnor, W. Kuhn, B. Kahn, W. Gebhardt, J. Cryst. Growth 138, 412 (1994). 8. R.L. Gunshor, L.A. Kolodziejski, N. Otsuka, S. Datta, Surf. Sci. 174, 522 (1986). 9. U. Pal, S. Saha, A. K. Chaudhari, V.V. Rao, H.D. Benarji, J. Phys. D: Appl. Phys. 22, 965 (1989). 10. R. Sarma, N. Mazumdar and H.L. Das, Bull. Mater. Sci. 29, 11 (2006). 11. G.I. Rusu, P. Prepilita, N. Apetroaei and G. Popa, J. Optoelectron. Adv. M. 7(2), 829 (2005). 12. H. Belakhder, A. Outzourhit, E.L. Ameziane, Thin Solid Films 382, 30 (2001). 13. M. Neumann-Spallart, C. Konigstein, Thin Solid Films 265, 33 (1995). 14. A.B. Kashyout, A.S. Arico, P.L. Antonucci, F.A. Mohamed, V. Antonucci, Mater. Chem. Phys. 51, 130 (1997). 15. K.K. Mishra, K. Rajeshwar, J. Electroanal. Chem. 273, 169 (1989). 16. M.C. Lin, P.Y. Chen, I.W. Sun, J. Electrochem. Society 149, 653 (2001). 17. B. Bozzini, M.A. Baker, P.L. Cavallotti, E. Cerri, C. Lenardi, Thin Solid Films 388, 361 (2000). 18. S. Venkatachalam, D. Mangalaraj, Sa.K. Narayandass, K. Kim, J. Yi, Physica B 358, 27 (2005). 

https://essuir.sumdu.edu.ua/bitstream/123456789/9306/1/4_effect.PDF

Effect of substrate temperature on structural and morphological parameters of ZnTe thin films

Abstract

Similar works

Full text

Available Versions

SocioEconomic Challenges Journal (Sumy State University)

Electronic Sumy State University Institutional Repository