Pressure dependence of the fundamental band-gap energy of CdSe

Pressure-dependent photomodulation spectroscopic studies of the optical transition associated with the fundamental bandgap of single-crystal bulk CdSe are presented. Photomodulated transmission (PT) measurements were performed at room temperature as a function of applied hydrostatic pressure using the diamond-anvil-cell technique. The sharp, derivative-like PT spectral features corresponding to the band-gap transition in CdSe were found to shift linearly toward higher energy with increasing pressure. By examining the pressure dependence of the PT spectra, the pressure coefficient for the direct band gap of wurtzite CdSe was determined to be 43.1 meV/GPa. The hydrostatic deformation potential of the band gap was found to be -2.3 eV. (C) 2004 American Institute of Physics.