Charge-Carrier Collection in Superconducting Titanium Transition-Edge Sensors Deposited on High-Purity Silicon
We have found that superconducting titanium transition-edge sensors (TES) deposited on high-purity, monocrystalline silicon operate in two distinct “modes”, distinguished by different intrinsic gains. This difference may be due to changes in efficiency for prompt collection of the energy carried by electrons and holes; variously augmenting the dominant phonon-derived signals. Charge-carrier collection may be modulated by a space-charge region (Schottky-barrier) adjacent to the superconductor. We propose a model for this effect.