Field-effect transistors as tunable infrared detectors

Author

Marta Silva dos Santos Gusmão

Date of Award

12-1996

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Physics

Major Professor

Gerald D. Mahan

Committee Members

Geoffrey Canright, John Quinn, Marshall Pace

Abstract

Two problems are discussed in this thesis. In Part I, we present a theory of tun- able infrared response in metal-oxide-semiconductor field-effect transistor. Multipole plasmons are localized collective electronic oscillations which arise from a nonuniform density of electrons. We investigate whether multipole plasmons in semiconductor quantum well structures can be used as linear or nonlinear detectors of infrared ra- diation. The frequencies of these detectors can be tuned using a gate voltage. We study the response of the MOSFET to static and time-dependent electric field applied perpendicular to its interface metal-semiconductor. A time-dependent local density approximation is used to calculate the optical response. To achieve our goal, we calculated the linear α(ω) and the second-order β(ω) polarizability as function of the frequency of the applied electric field. If the separation between the lowest subbands is δ, then intersubband transitions require a photon energy ħω₁ = δ for one photon transitions, and 2ħω = δ for two photon transitions. The linear polarizability α(ω) has resonance at frequencies near ω₁, while the second-order polarizability β(ω) has resonance at frequencies near ω₂. There are some plots of the polarizabilities to show their resonant frequencies in function of the change in the gate voltage. In Part II, we calculated the ground-state energy of the metallic hydrogen and potassium by Hartree-Fock variational method.

Recommended Citation

Santos Gusmão, Marta Silva dos, "Field-effect transistors as tunable infrared detectors. " PhD diss., University of Tennessee, 1996.
https://trace.tennessee.edu/utk_graddiss/9749