Study and application of colloidal systems for obtaining CdTe+Te thin films by spray pyrolysis

- N4OH was used to stabilize at CdTe colloidal.
- CdTe thin film was obtained by spray pyrolysis. CdTe colloidal was used to deposit.
- Photovoltaic effect was observed in the CdS/CdTe heterojunction.
- This processes can used to fabricated solar cells to industrialize scale.

In this work, a new aqueous colloidal dispersion of CdTe was prepared and stabilized using NH4OH. Results shows, two different sizes of CdTe (20 nm and 60 nm widths) presented in solution. From this dispersion, CdTe thin films around 500 nm thicknesses were deposited by spray pyrolysis technique. Experimental conditions, dispersion composition, rheology and annealing temperature were optimized to obtain dense and crack-free CdTe thin films. CdTe thin films were characterized in regarding the optical, phase composition and structural properties. X-ray diffraction patterns indicates, face-centered cubic CdTe structure in bulk. Also, an additional diffraction plane corresponding to the hexagonal elemental tellurium (Te) was observed indicating a secondary phase over the film surface. Finally, it was found that such Te phases corresponds to nanorod-like morphology.

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