Analysis of approximations used in terahertz quantum cascade laser doping calculations

The common approximations used in the ionized donor density calculations of terahertz quantum cascade lasers (TQCL's) are investigated. Each approximation is computationally analyzed in order to determine its impact on the accuracy and speed of the doping calculations. The analyses are repeated across all of the lattice temperatures and donor densities that are typical in TQCL's (T = 1 to 300 K, N-D = 1.00 to 5.00 x 10(16) cm(-3)). Additionally, an original optimized approximation is proposed and analyzed. This optimized approximation is found to out-perform the common approximations in both accuracy and speed in all cases.