Effect of boron doping on first-order Raman scattering in superconducting boron doped diamond films

Abstract

Aggregation of impurity levels into an impurity band in heavily boron doped diamond results in a background continuum and discrete zone centre phonon interference during the inelastic light scattering process. In order to understand the Raman scattering effect in granular BDD films, systematically heavily doped samples in the semiconducting and superconducting regimes have been studied using the excitation wavelengths in the UV and visible regions. A comprehensive analysis of the Fano resonance effect as a function of the impurity concentrations and the excitation frequencies is presented. Various Raman modes available in BDD including signals from the grain boundaries are discussed. The authors would like to thank the financial support from the Department of Science and Technology (DST) that led to the establishment of the Nano Functional Materials Technology Centre (NFMTC)(SR/NM/NAT/02-2005). The ion beam laboratory facility and the staff at the Institute of Physics (IOP) are acknowledged for their valuable service provided for carrying out PIGE measurements. Also, we would like to thank Professor P. V. Satyam and his group at IOP and Dr. Ashutosh Rath for carrying out cross-sectional TEM and PIGE experiments.