Modelling and optimizing of high sensitivity semiconducting thermistors at low temperature

We have modelled low temperature semiconducting thermometers by using a semi-analytical approach of Anderson insulators, taking into account both the electrical field and the electron/phonon decoupling effects. We first used this simulation to fit measured V(I) curves to validate this method and to obtain physical parameters of NTD Ge and NbSi thin film samples around 100 mK. We show that considering the two effects separately leads to an overestimate of each one. Once validated, our algorithm was used to optimise the design of high sensitivity thermometers for the High Frequency Instrument (HFI) of the Planck satellite.