Evaluation of cadmium telluride (CdTe) thin films grown at different annealing temperatures for efficient terahertz generation

Electrodeposition of cadmium telluride (CdTe) on fluorine doped tin oxide (FTO) using two electrode configurations was successfully achieved with the main focus on the growth temperature. The electroplating temperatures explored ranged between 55 and 85 °C for aqueous electrolytes containing 1.5 M cadmium nitrate tetrahydrate (Cd(NO3)2·4H2O) and 0.002 M tellurium oxide (TeO2). The ensuing CdTe thin-films were characterized using X-ray diffraction (XRD), UV-Vis spectrophotometry, scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and photoelectrochemical (PEC) cell measurements. The electroplated CdTe thin-films exhibit a dominant (111) CdTe cubic structure, while the crystallite size increases with the increase in the electroplating temperature. The dislocation density and the number of crystallites per unit area decrease with increasing growth temperature. The optical characterization depicts that the CdTe samples show comparable absorbance and a resulting bandgap of 1.51 ± 0.03 eV for as-deposited CdTe layers. A marginal increase in the bandgap and reduction in the absorption edge slope towards lower deposition temperatures were also revealed. The annealed CdTe thin-films showed improvement in the energy bandgap as it tends towards 1.45 eV while retaining the aforementioned absorption edge slope trend. Scanning electron microscopy shows that the underlying FTO layers are well covered with increasing grain size observable relative to the increase in the deposition temperature. The energy dispersive X-ray analyses show an alteration in the Te/Cd relative to the deposition temperature. Higher Te ratio with respect to Cd was revealed at deposition temperature lower than 85 °C. The photoelectrochemical cell study shows that both p- and n-type CdTe can be electroplated and that deposition temperatures below 85 °C at 1400 mV results in p-type CdTe layers.

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Factors Affecting Electroplated Semiconductor Material Properties: The Case Study of Deposition Temperature on Cadmium Telluride

10.20944/preprints201904.0129.v1 ◽

2019 ◽

Author(s):

Ayotunde A. Ojo ◽

I.M. Dharmadasa

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Scanning Electron Microscopy ◽

Cadmium Telluride ◽

Absorption Edge ◽

Growth Temperature ◽

Deposition Temperature ◽

X Ray ◽

Cdte Thin Films ◽

Scanning Electron

Electrodeposition of cadmium telluride (CdTe) on fluorine doped tin oxide (FTO) using two electrode configuration was successfully achieved with the main focus on the growth temperature. The electroplating temperatures explored ranges between (55 and 85)℃ for aqueous electrolytes containing 1.5 M cadmium nitrate tetrahydrate (Cd(NO3)2 •4H2O) and 0.002 M tellurium oxide (TeO2). The ensuing CdTe thin-films were characterised using X-ray diffraction (XRD), UV-Vis spectrophotometry, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and photoelectrochemical (PEC) cell measurements. The electroplated CdTe thin-films exhibit a dominant (111) CdTe cubic structure, while the crystallite size increases with the increase in the electroplating temperature. The internal strain, dislocation density and the number of crystallites per unit area decrease with increasing growth temperature. The optical characterization depicts that the CdTe samples show comparable absorbance and a resulting bandgap of 1.51±0.03 eV for as-deposited CdTe layers. A marginal increase in the bandgap and reduction in the absorption edge slope towards lower deposition temperatures were also revealed. The annealed CdTe thin-films showed improvement in energy bandgap as it tends towards 1.45 eV while retaining the aforementioned absorption edge slope trend. Scanning electron microscopy shows that the underlying FTO layers are well covered with increasing grain size observable relative to the increase in the deposition temperature. The energy dispersive X-ray analyses show an alteration in the Te/Cd relative to the deposition temperature. Higher Te ratio with respect to Cd was revealed at deposition temperature lower than 85℃. The photoelectrochemical cell study shows that both p- and n-type CdTe can be electroplated and that deposition temperatures below 85℃ at 1400 mV results in p-type CdTe layers.

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Effect the Thickness on the Electrical Properties and (I-V) Character of the (CdTe) Thin Films and Find the Efficiency of Solar Cell CdTe/CdS

Baghdad Science Journal ◽

10.21123/bsj.15.2.192-197 ◽

2018 ◽

Vol 15 (2) ◽

pp. 192-197

Author(s):

Baghdad Science Journal

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Solar Cell ◽

Electrical Properties ◽

Room Temperature ◽

Annealing Temperature ◽

Annealing Temperatures ◽

Evaporation Technique ◽

Cdte Thin Films ◽

Vacuum Evaporation Technique

Thin films of CdTe were prepared with thickness (500, 1000) nm on the glass substrate by vacuum evaporation technique at room temperature then treated different annealing temperatures (373,473,and 573)K for one hour. Results of the Hall Effect and the electrical conductivity of (I-V) characteristics were measured in darkness and light.at different annealing temperature results show that the thin films have ability to manufacture solar cells, and found that the efficient equal to (2.18%) for structure solar cell (Algrid / CdS / CdTe /glass/ Al) and the efficient equal to (1.12%) for structure solar cell (Algrid / CdS / CdTe /Si/ Al) with thick ness of (1000) nm with CdTe thin films at RT.

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Solar cells based on CdTe thin films

Фізика і хімія твердого тіла ◽

10.15330/pcss.22.4.817-827 ◽

2021 ◽

Vol 22 (4) ◽

pp. 817-827

Author(s):

T.M. Mazur ◽

V.V. Prokopiv ◽

M.P. Mazur ◽

U.M. Pysklynets

Keyword(s):

Thin Film ◽

Thin Films ◽

Solar Cells ◽

Cadmium Telluride ◽

Large Scale ◽

Scale Production ◽

Photoelectric Conversion ◽

Technical Problems ◽

Suitable Material ◽

Cdte Thin Films

An analysis of the use of semiconductor solar cells based on thin-film cadmium telluride (CdTe) in power engineering is carried out. It is shown that the advantages of thin-film technology and CdTe itself as a direct-gap semiconductor open up the prospect of large-scale production of competitive CdTe solar modules. The physical and technical problems of increasing the efficiency of CdS/CdTe heterostructure solar cells, which are significantly inferior to the theoretically possible value in mass production, are discussed. The state of CdTe thin-film solar cells, which make CdTe a suitable material for ground-based photoelectric conversion of solar energy, the historical development of the CdTe compound, the application of CdTe thin films, the main methods and strategies of device production, device analysis and fundamental problems related to the future development of thin-film modules based on cadmium telluride.

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Evaluation of the Effect of Deposition pH on the Physico-chemical Properties of Electrochemically Deposited Cadmium Telluride for Photovoltaic Device Applications

European Journal of Engineering and Technology Research ◽

10.24018/ejers.2021.6.6.2404 ◽

2021 ◽

Vol 6 (6) ◽

pp. 1-7

Author(s):

Ayotunde A. Ojo ◽

Kolade A. Olanipekun ◽

Benjamin S. Oluwadare ◽

Taiwo O. Oni

Keyword(s):

Thin Films ◽

Cadmium Telluride ◽

Electrochemical Deposition ◽

Absorption Edge ◽

Ph Value ◽

Photoelectrochemical Cell ◽

Cadmium Nitrate ◽

Electrolytic Bath ◽

X Ray ◽

Cdte Thin Films

Two-electrode (2E) configuration was successfully utilised in the electrochemical deposition of cadmium telluride (CdTe) on fluorine-doped tin oxide (FTO) substrate with the main emphasis on the electrolytic bath pH. The electrochemical deposition pH explored is within the range of (1.00 to 6.00)±0.02 for the aqueous electrolyte comprising of tellurium oxide (TeO2) and cadmium nitrate (Cd(NO3)2) which are the respective precursors of Te and Cd. The optical, structural, morphological, compositional, and electrical properties of the electroplated CdTe thin-films were respectively explored using UV-Vis spectrophotometry, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and photoelectrochemical (PEC) cell measurements. The optical characterisation show that the CdTe samples exhibit dissimilar absorbance depending on the growth pH for both the as-deposited layers and post-growth treated CdTe layers. A decrease in the absorption edge slope and dip in the bandgap was observed away from pH2. The bandgap of the post-growth treated CdTe layers showed enhancement as it leans towards 1.45 eV, with the trend retention of absorption edge slope, similar to the as-deposited CdTe layers. The electrodeposited CdTe thin-films show a dominant orientation along the cubic (111) CdTe plane, while both the the calculated crystallite size and the XRD peak intensity Pi decreases with the electroplating pH outside the (2.00 to 3.00)±0.02 range. The EDX analyses depicts an alteration in the ratio of Cd to Te atomic percentage relative to the pH of the electrolyte. Comparatively high Te atomic ratio was observed at lower pH values and vice versa with increase alkalinity of the electrolyte. The obtained morphology depicts that the underlying FTO layers are well covered with a gradual reduction in the grain size of the CdTe observable away from pH value (2.00 and 3.00). The photoelectrochemical cell study depicts that the conduction type of the CdTe layers can also be attributed to the CdTe-electrolytic bath pH value.

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