Photoelectron transportation dynamics in GaAs photocathodes

We report here a general theory describing photoelectron transportation dynamics in GaAs semiconductor photocathodes. Gradient doping is incorporated the model through inclusion of directional carrier drift. The time-evolution electron concentration active layer upon injection an excitation pulse solved both numerically and analytically. predictions are compared with experiments via carrier-induced transient reflectivity change, which measured for gradient-doped uniform-doped photocathodes using femtosecond pump-probe reflectometry. Excellent agreement found between theory, leading to characterization key device parameters such as diffusion constant decay rates. Comparisons also made uniform gradient their characteristics transportation. Doping be able accelerate accumulation on surface. These results offer new insights into III-V potentially open avenue toward experimental parameters.