An improved apparatus for surface photovoltage studies with a bimorphous piezoelectric Kelvin probe

Abstract
An improved apparatus for measuring surface photovoltage spectra of semiconductors is described in which a boss-shaped Kelvin reference electrode is oscillated by using a bimorphic piezoelectric driver. A sensitivity of 0.1 mV is achieved. The apparatus is small in size, easy to handle and is compatible with the VSK 4-300 Leybold Heraeus optical cryostat allowing the range from liquid helium to room temperature to be covered.