DETERMINATION OF FREE-CARRIER CONCENTRATION IN N-GAINP ALLOY BY RAMAN-SCATTERING

We present results of Raman scattering from coupled phonon-plasmon mod es in Se-doped n-Ga0.52In0.48P alloy. Due to the small energy separati on between the Gamma- and the L-point conduction-band minima for this alloy composition, a significant fraction of the free carriers at room temperature are present in the L-conduction-band valley, giving rise to a multicomponent plasma. The carrier concentrations extracted from the Raman spectra for the different epilayers are in good agreement wi th the free electron concentrations determined by capacitance-voltage measurements. We employ the light scattering technique to extract the carrier concentration in the n-type emitter layer of a GaInP-based sol ar cell. (C) 1995 American Institute of Physics.