Characterization of semiconductor heterojunctions using internal photoemission

Internal photoemission is a photoelectric characterization technique commonly used to study semiconductor heterojunction characteristics. Previous analyses of internal photoemission including those of Fowler, Kane, and Powell have been well accepted and applied; however, the quantum effects were not fully taken into account. We examined the quantum effects on internal photoemission spectra and found that the photoemission yield, Y(h nu), is proportional to (h nu - E(T))(gamma), where h nu is the photon energy, E(T) is the threshold energy, and gamma is a constant determined by the emitter density of states, the transmission probability, and the collector conduction band density of states, respectively. (C) 1996 American Institute of Physics.