Influence of Bath Temperature, Deposition Time and S/Cd Ratio on the Structure, Surface Morphology, Chemical Composition and Optical Properties of CdS Thin Films Elaborated by Chemical Bath Deposition

Abstract

Cadmium sulphide (CdS) thin films were deposited on glass substrates by the chemical bath deposition (CBD) method, using anhydrous cadmium chloride (CdCl 2 ) and thiourea (CS(NH 2 ) 2 ) as sources of cadmium and sulphur ions respectively. The influence of bath temperature (T b ), deposition time (t d ) and [S]/[Cd] ratio in the solution on the structural, morphological, chemical composition and optical properties of these films were investigated. XRD studies revealed that all the deposited films were polycrystalline with hexagonal structure and exhibited (002) preferential orientation. The films deposited under optimum conditions (T b = 75˚C, t d = 60 min and [S]/[Cd] ratio = 2.5) were relatively well crystallized. These films showed large final thickness and their surface morphologies were composed of small grains with an approximate size of 20 to 30 nm and grains grouped together to form large clusters. EDAX analysis revealed that these films were nonstoichiometric with a slight sulphur deficiency. These films exhibited also a transmittance value about 80% in the visible and infra red range.

Studying the Effect of Deposition Time on Optical Properties of CdS Thin Films

“…this obvious that the films made up of nanocrystal particles this agreement with [17], the range of 2θ 20̊ to 80. In fact, CdS has three forms of structure are cubic, hexagonal and rock salt, the structure more stable is the hexagonal phase due to the method of preparation cadmium sulfide in addition to be the structure more favorable for manufacturing of a solar cells [1] .…”

The deposition of thin films of cadmium zinc sulfide Cd1−x Zn x S at 250 °C from spin-coated xanthato complexes: a potential route to window layers for photovoltaic cells

“…Numerous techniques have been used to grow CdS and Cd 1-x Zn x S thin films including dip coating [16], electrodeposition [17], chemical vapor deposition (CVD) [18], aerosol-assisted CVD (AA-CVD) [19][20][21], chemical bath deposition (CBD) [2,8,22,23], spray pyrolysis [24,25], thermal evaporation [26], successive ionic layer and reaction (SILAR) [27], thermolysis [28,29], electrochemical atomic layer epitaxy (ECALE) [11], sol-gel spin coating, [30,31] doctor's blade, [32] and others [14,21,33,34]. Spin coating (SC) is a particularly useful method for the deposition of thin films [35,36].…”

Detailed Analysis of Five Aspects Addressed to Minimize Costs and Waste in the Chemical Bath Deposition of CdS Films Using the Cd<i>B</i>–<i>A</i>C<sub>6</sub>H<sub>5</sub>O<sub>7</sub>–<i>A</i>OH–(NH<sub>2</sub>)<sub>2</sub>CS System

“…However, several authors have reported explicitly or implicitly that the lower the reaction temperature the lower the thin film growth rate [12,15,20,21,23,28,34,35,54,[77][78][79][80][81]84,87,90,[103][104][105][106][107][108][109][110][111][112][113][114][115][116][117][118][119][120][121]. Thus, without delving into the cases in which homogeneous precipitation is favored, which limits the maximum d-a limit which was directly reported [12,15,21] or simply evident in the results reported [115,118,120] by some authors-the use of low temperatures lengthens the time required to achieve a thin film with determined d compared to the time required at higher temperatures. For example, Figure 5 shows the log(T -1 ) value at 400 nm of the CdS thin films synthesized by using the economical formulation at different temperatures and different immersion times, and it confirms the increase in thin film growth rate with increasing temperature.…”