Surface dependent behaviour of CdS LO-phonon mode

Abstract

In this paper, we develop a sensitive optical method to monitor the surface roughness in the investigation of surfaces. By applying this method to measure the RMS surface roughness of various surfaces, we found RMS values which are comparable to those obtained by atomic force microscopy measurements. In addition, we present a simple empirical model to calculate the RMS surface roughness which shows very good agreement with the surface roughness measurements taken by the method reported in this paper. Finally, the application of our method to the study of the LO-phonon mode of CdS suggests that its intensity is dominated by the surface roughness. This roughness dependent behaviour of the CdS LO-phonon mode is experimentally confirmed by using an excitation wavelength near its E0 transition.

Effect of substrate temperature on implantation doping of Co in CdS nanocrystalline thin films

“…10,33 It is known that rough surfaces can enhance the light scattering cross-section. 34 Our AFM measurements reveal an increase in the surface roughness with increasing ion fluence as described below. Fig.…”