In this paper, the noise equivalent power (NEP) of an optical sensor based on
graphene-superconductor junctions in the constant current mode of operation has been
calculated. Furthermore, the necessary investigations to optimize the device noise with
respect to various parameters such as the operating temperature, magnetic field, device
resistance, voltage and current bias have been presented. By simultaneously solving the
free energy and charge carrier density equations of graphene at low temperature, the
specific heat, thermal interaction of electron-phonon and current responsivity of the
sensor have been calculated. Using these parameters, the noise equivalent power of the
device has been obtained. The results show that the behavior of device NEP by
increasing the magnetic field at a constant temperature is at first ascending and then
descending. The NEP value for different temperatures, up to T=80K, has an increasing
behavior and then by further increasing the temperature, the NEP will show decreasing
behavior which is also dependent on the value of the magnetic field. The NEP value is
directly related to the device voltage and current values, therefore by increasing the
voltage and current, the NEP will increase. Our investigations show that at the constant
current bias mode of operation, the final device NEP is independent of the device
resistance. پرونده مقاله