A MODEL NOISE TEMPERATURE FOR NONLINEAR TRANSPORT IN SEMICONDUCTORS

We present an analytical modeling of the noise temperature associated with velocity fluctuations obtained in the framework of the linear-res ponse theory around a steady state. The expressions are rigorously rel ated to an eigenvalue expansion of the response matrix and are applica ble to ohmic as well as to nonohmic (hot-carrier) conditions. Theory r equires as input parameters the reciprocal carrier effective mass, the drift velocity, the carrier energy, the variance of velocity fluctuat ions, and the covariance of velocity-energy fluctuations as functions of the electric field in stationary and homogeneous conditions. The an alytical results obtained for the case of holes in Si and electrons in GaAs at T=300 K are validated by comparison with experiments. (C) 199 6 American Institute of Physics.