Speaker
Description
We propose a novel detection scheme that utilizes the piezo-pyroelectric properties of ZnO thin films. The aim is to realize a zero external bias vacuum ultraviolet (VUV) detector that can be used in liquid noble time projection chambers. We present initial results from our measurements that test our hypothesis that stress-induced in ZnO thin films through interface strain engineering can lead to an enhancement of the VUV photoinduced signals. We compare the signals from a bare ZnO detector in a vertical geometry to a detector with an additional silicon nitride layer that introduces the stress-induced piezo potential. In addition, we demonstrate the detector performance at cryogenic temperatures, and the results are discussed based on piezo- and pyro-electric potential induced in ZnO thin film. COMSOL simulations of the stress and temperature variation induced potential in bare Zno and in a ZnO/silicon nitride heterostructure will be used to optimize the device architecture. Through the optimization of the device architecture, we expect that the stress-induced potential can produce measurable signals under zero bias and low light conditions. Such a photodetector can have applications in rare event searches using liquid noble detectors, potentially for solar energy harvesting and the development of metamaterial broadband solar absorbers for near-perfect absorption in the UV to Visible wavelengths.
