Structural evolution and optical characterization of indium doped cadmium sulfide thin films obtained by spray pyrolysis for different substrate temperatures

• Published in: Solar energy materials and solar cells 2004-05, Vol.82 (1), p.11-20
• Main Authors: Acosta, Dwight R., Magaña, Carlos R., Martı́nez, Arturo I., Maldonado, Arturo
• Format: Article
• Language: English
• Subjects: Applied sciences; Cadmium sulfide; Electron microscopy; Energy; Exact sciences and technology; Natural energy; Photovoltaic conversion; Solar cells. Photoelectrochemical cells; Solar energy; Spray pyrolysis; Structural properties
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2004.01.001

Indium doped cadmium sulfide thin films were prepared by spray pyrolysis on glass substrates at different temperatures ranging from 300°C to 450°C in 25°C steps, using aqueous solution of copper chloride and thiourea salts. We used In(COOH) 3 as the dopant. Structural characterization was carried out by X-ray diffractometry and scanning electron microscopy and high resolution electron microscopy were used together with atomic force microscopy (AFM) to follow the evolution of structural and morphological parameters of the films with substrate temperature ( T s). At least two preferential growth, (1 1 2) for samples with T s between 325°C and 400°C and (0 0 2) for T s between 400°C and 450°C, respectively were detected. For the films obtained at higher substrate temperatures, HREM micrographs revealed the presence of a large number of structural defects together with nanostructured configurations. AFM revealed surface modifications of CdS:In grains at higher substrate temperature. The substrate temperature is directly related with the shift detected in the band gap values derived from optical of parameters.