FIZIKA A 11 (2002) 1 , 31-42

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RAMAN AND PHOTOLUMINESCENCE STUDIES OF PURE AND Sn-ENRICHED THIN FILMS OF CdS PREPARED BY SPRAY PYROLYSIS

I. K. BATTISHAa, H. H. AFIFYa, G. ABD EL FATTAHb and Y. BADRb

aSolid State Physics Department, National Research Centre (NRC), Cairo, Egypt

bNational Institute of Laser Enhancement Sciences (NILES), Cairo University, Egypt

Received 10 September 2000; revised manuscript received 16 September 2001
Accepted 5 November 2001        Online 25 May 2002

Thin films of CdS, pure and enriched with different concentrations of tin up to 6%, were prepared by the spray pyrolysis technique. All samples were prepared at the deposition temperature of 420 C. The XRD diagnostic data of the investigated samples revealed the polycrystalline nature of the as-deposited samples. The main characteristic peaks of CdS appeared in both pure and enriched films prepared by all used methods. The enrichment of Sn has no effect on positions of the characteristic peaks. The observed effect of Sn enrichment is the change in peak broadening which increases with the increase of Sn concentration. The thickness values ranged from 0.65 up to 1.15 mm. The samples of pure CdS show a sharp absorption edge at about 2.43 eV. The absorption coefficient a of the investigated samples was calculated from transmission and reflection spectra. Photoluminescence measurements show red emission band of the as-deposited samples, which was quenched by Sn incorporation. This band is ascribed to the excess of Cd which was checked by the energy dispersive X-ray (EDX) spectrometry. Raman spectra of samples with different concentrations of Sn were studied. They show remarkable increase of intensity when increasing the film thickness and decreasing the Sn concentration.

PACS numbers: 78.30.-j, 78.66.-m, 68.55.Ln
UDC 538.958, 538.975

Keywords: pure and Sn-enriched CdS thin films, spray pyrolysis technique, polycrystalline, light absorption coefficient, photoluminescence, Raman spectra

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