Abstract

Because of the lack of momentum conservation in optical transitions, the temporal evolution of photogenerated carriers in a-Si:H cannot simply be measured from the spectral dependence of the induced absorption Δα. For ħω_probe < E_G, Δα corresponds to intraband (electronic) absorption and is proportional to N and the optical cross section σ. For ħω_probe > E_G, interband absorption which is sensitive to lattice temperature through bandgap renormalization also plays an important role.

© 1990 Optical Society of America