Partial and total α parameters in semiconductor optical devices

α parameters due to partial variation of carrier density (αN) or temperature (αT) are calculated for a two-dimensional semiconductor. We also introduce and investigate the total alpha parameter (αt) due to simultaneous variations of the carrier density and temperature. We find that, unlike the usual αN, the partial αT and total αt show quite different behavior with changes in underlying variables and could be positive, negative, or singular.