FIR photovoltaic effect in a boron-doped silicon structure

A new FIR photovoltaic effect, which does not depend on incident radiation intensity, is found at low temperatures in modulated unipolar boron-doped s ilicon structure. It is shown that the effect originates from an asymmetric ballistic hole transport across the low doped layer due to fast trapping p rocess within the upper Hubbard impurity band of the doped layer. The analy sis of the temperature dependence of the photovoltage gives the Fermi energ y in the impurity band. (C) 2000 Published by Elsevier Science B.V. All rig hts reserved.