An analytic approach to the LSA mode

The conditions necessary for operation in the limited space-charge accumulation (LSA) mode, and the efficiencies that can be obtained, have been calculated for a range of low-field mobilities in GaAs. The analysis follows the theory published by Copeland, but the expression chosen to describe the velocity field characteristics allows direct solution of the integrals that occur in the theory, and the extension of the results to include GaAs with differing values of low-field mobility. It has therefore been possible to present equations for the various parameters of interest, which are a function of low-field mobility. The results of the calculations indicate that efficiency increases with low-field mobility, but the range of values of electron concentration/frequency becomes more restricted as the mobility is increased.