Physical Properties of Cadmium Sulphur Films Obtained at Different pH Values

Yıl 2017, Cilt: 38 Sayı: 3, 507 - 515, 30.09.2017

Ahmet Şenol Aybek Hilal Rüzgar

https://doi.org/10.17776/csj.340501

Öz

Cadmium sulphide films have
been deposited onto the glass substrates by chemical bath deposition method at
different pH values (10.00, 10.10, 10.20, 10.30) at 80 ^oC. X-ray
diffraction spectra of the films have shown that the films are cubic in
structure. To determine the optical properties of the CdS films UV-vis
spectrophotometer was used. Optical absorption and transmittance optical values
of the films were determined from the absorbance measurements in the visible
range. It has been found that the forbidden energy band gap values of the films
decrease with increasing pH values and change between 2.42-2.38 eV. The
transmission efficiency of CdS films were exhibit about between 84%-65% in the
visible region. The surface properties and roughness values of the films were
determined using atomic force microscopy. FESEM images show that the films are
generally homogeneous distribution in spherical structure. The elemental composition of the films was determined
from the EDX study. 

Anahtar Kelimeler

CdS, pH effect, Structural Properties, Optical Properties

Farklı pH Değerlerinde Elde Edilen Kadmiyum Sülfür Filmlerinin Fiziksel Özellikleri

Öz

Bu çalışmada, kimyasal banyo depolama metodu
kullanılarak 80 °C banyo sıcaklığında cam tabanlar üzerine farklı pH
değerlerinde (10,00; 10,10; 10,20; 10,30) kadmiyum sülfür yarıiletken filmleri
elde edilmiştir. Elde edilen filmlerin X-ışını kırınım desenlerinden kübik
fazda oluştuğu görülmüştür. Filmlerin soğurma ve geçirgenlik spektrumları
UV-Vis spektrofotometre ile alınmıştır. Filmlerin bant aralığı değerleri
görünür bölgedeki soğurma spektrumu ölçümlerinden elde edilmiştir. Filmlerin
yasak enerji bant aralığı değerlerinin artan pH değerleriyle birlikte azaldığı
ve 2,42-2,38 eV arasında değiştiği tespit edilmiştir. Filmlerin görünür
bölgedeki optik geçirgenlik değerleri %84-65 arasında değiştiği bulunmuştur.
Filmlerin yüzey özellikleri ve pürüzlülük değerleri atomik kuvvet mikroskobu
kullanılarak belirlenmiştir. FESEM görüntülerinden filmlerin genellikle küresel
yapıda homojen dağılım gösterdiği gözlenmiştir. Filmlerin
elemental bileşimini tayini EDX kullanılarak yapılmıştır.

Anahtar Kelimeler

CdS, pH Etkisi, Yapısal Özellikler, Optiksel Özellikler

Kaynakça

• [1]. Enríquez, J.P. and Mathew, X. Influence of the thickness on structural, optical and electrical properties of chemical bath deposited CdS thin films. Sol. Energy Mater. Sol. Cells, 2003; 76, 313-322.
• [2]. Kim, D.J., Yu, Y.-M., Lee, J.W., Choi, Y.D. Investigation of energy band gap and optical properties of cubic CdS epilayers. Appl. Surf. Sci. 2008; 254, 7522-7526.
• [3]. Pradhan, B., Sharma, A.K., Ray, A.K. Conduction studies on chemical bath- deposited nanocrystalline CdS thin films. J. Cryst. Growth. 2007; 304, 388-392.
• [4]. Sivaraman T., Nagarethinam V.S., Balu A.R. CdS thin films Fabricated by a simplified Spray technique from different Substrate Temperatures – Structural, Morphological, Optical and Electrical analysis. Res. J. Material Sci. 2014; 2 (2), 6-15.
• [5]. Zyoud, A., Saa'deddin, I., Khudruj, S., Hawash, Z.M., Park, D., Campet, G., Hilal, H.S. CdS/FTO thin film electrodes deposited by chemical bath deposition and by electrochemical deposition: A comparative assessment of photo-electrochemical characteristics. Solid State Sci. 2013; 18, 83–90.
• [6]. Kong, L., Li, J., Chen, G., Zhu, C., Liu, W. A comparative study of thermal annealing effects under various atmospheres on nano-structured CdS thin films prepared by CBD. J. Alloys Compd. 2013; 573, 112–117.
• [7]. Metin, H., Esen, R. Annealing studies on CBD grown CdS thin films. J. Cryst. Growth. 2003; 258 (1–2), 141–148.
• [8]. M. Kundakci, A. Ateş, A. Astam, M. Yildirim. Structural, optical and electrical properties of CdS, Cd0.5In0.5S and In2S3 thin films grown by SILAR method. Physica E. 2008; 40, 600–605.
• [9]. Lee, J. Comparison of CdS films deposited by different techniques: Effects on CdTe solar cell. Appl. Surf. Sci. 2005; 252 (5), 1398–1403.
• [10]. G. Pérez-Hernández, J. Pantoja-Enríquez, B. Escobar-Morales, D. Martinez-Hernández, L.L. Díaz-Flores, C. Ricardez-Jiménez, N.R. Mathews, X. Mathew. A comparative study of CdS thin films deposited by different techniques. Thin Solid Films. 2013; 535, 154-157.
• [11]. Kwon, J.-H., Ahn, J.-S. and Yang, H. Chemical bath deposition of CdS channel layer for fabrication of low temperature-processed thin-film-transistors. Curr. Appl. Phys. 2013; 13, 84–89.
• [12]. Sam, M., Bayati, M.R., Mojtahedi, M., Janghorban, K. Growth of Cu2S/CdS nano-layered photovoltaic junctions for solar cell applications. Appl. Surf. Sci. 2010; 257, 1449–1453.
• [13]. Huang L., Wei Z.L., Zhang F.M., Wu X.S. Electronic and optical properties of CdS films deposited by evaporation. J. Alloys Compd. 2015; 648, 591-594.
• [14]. Yücel, E., Güler, N. Yücel, Y. Optimization of deposition conditions of CdS thin films using response surface methodology. J. Alloys Compd. 2014; 589, 207–212.
• [15]. B.D. Cullity, S.R. Stock, Elements of X-ray Diffraction Prentice-Hall, Upper Saddle River, NJ (2001).
• [16]. Metin, H., Esen, R. Annealing effects on optical and crystallographic properties of CBD grown CdS films. Semicond. Sci. Technol. 2003; 18, 647–654.
• [17]. Aybek, A.S., Rüzgar, H. Effect of The pH on Crystal Structural, Optical and Surface Morphological Properties of The Cds Films Deposited By Chemical Bath Deposition. Chalcogenide Letters. 2016; 13 (8), 339–350.