Modeling impurity-band conduction infrared detectors
Abstract
This thesis describes an approach to be followed in modeling Impurity-Band Conduction (IBC) infrared detectors. By treating the impurity band like a "valence" band, the transport problem is formulated in terms of the drift-diffusion equations. To compute the electron mobility a semi-empirical model which predicts the electron mobility as a function of electric filed, doping density, and temperature has been developed. The approach integrates empirical formulas relating drift velocity and mobility to electric field, experimental data for pure silicon, the theory of scattering rate scaling, and the simulation of electron transport via the Monte Carlo method. The value of hopping mobility employed in the active region is the constant value derived by Montroy, Baron, Albright, et al., which is based on a simple model for the transport of charge in the linearly decreasing field of the active region. A critical review is presented on the techniques to compute the hopping mobility numerically and one such technique is proposed. The proposed technique models the hopping transport as a steady-state diffusion-like process to nearest empty atoms. The device modeling problem as it applies to the IBC device is formulated allowing, among other things, for a doping-dependent activation energy. The code that embodies the device model, IBCSIM, is then applies in a parametric study of the IBC device.
Degree
Ph.D.
Advisors
Gray, Purdue University.
Subject Area
Electrical engineering
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.