ELECTRON BEAM MODULATED REFLECTANCE OF GERMANIUM

Abstract
A technique for modulation of the reflectance of germanium in the 2–3‐eV range by means of a periodically gated electron beam is described. The relative reflectance curves resemble the thermoreflectance results, but the amplitude varies with the one‐third power of the excess carrier density. The results agree with a theory that at large excess carrier densities the mean distance between carriers is small enough to cause a modification of the crystal potential and therefore to lower critical point transition energies.