Effect of laser-irradiation on structural and electrical properties of CdS thin films

CdS films were deposited by a resistive heating technique onto glass substrates kept at 150 °C. The films were irradiated with laser pulses of various energy densities. A pulsed laser (Nd-doped yttrium aluminum garnet) capable of producing a 20-ns pulse of 0.53 μm wavelength (frequency doubled) with varying energy densities (2–50 mJ/cm2 ) was employed. X-ray diffraction studies showed that the crystallinity of the films improved with laser irradiation. dc conductivity and Hall coefficient measurements were made on the films in the temperature range 77–300 K for both as-grown and laser-irradiated films. It was observed that both the Hall coefficient and mobility increased with an increase of energy density as well as the number of pulses. Typically, the mobility increased from 71 to 121 cm2 V−1 s−1 after irradiation with 50 laser pulses of energy density 28 mJ/cm2 .