Semiconductor Particle Detector based on Work Function Modulation*

A novel type of solid state particle detector has been designed and investigated. The essential design is a bandgap reference circuit with a Schottky diode comprised of gallium nitride, a semiconducting piezoelectric material, designed to output the Schottky barrier height. As a semiconductor, this material exhibits an electrical response to high-energy particle impingement through the creation of electron-hole pairs. It also exhibits an additional and very unique type of response to lattice vibrations induced in the crystal lattice by momentum transfer from the incident particle. These acoustic waves create mechanical strain which induces an in-phase signal via the piezoelectric effect, which subsequently modulates the effective barrier height of the Schottky diode. This talk presents functional demonstration of a prototype circuit and transient responses to neutron irradiation.