Study on Phonon Amplification of Neganov–Luke Light Detectors

Abstract

We report progress on the development of a light detector with Neganov–Luke (NL) phonon amplification. Double comb-like electrodes were fabricated on an intrinsic Si wafer to apply an electric field. A metallic magnetic calorimeter was used for a sensitive measurement of the temperature increase originating from the light absorption in the wafer and NL phonon amplification. The NL light detector was applied to the simultaneous detection of heat and light signals from a $$\hbox {ZnWO}_4$$ scintillating crystal. Clear amplification of the light signals was obtained for various voltages applied to the electrodes, while no change in the heat signals was observed. The voltage dependence of the measured gain was investigated for a few efficiency parameters, such as the saturation voltage required to suppress the recombination of electron-hole pairs and the heat generation efficiency of the NL effect.