Optical response functions of semiconductors: Nearly first-principles calculations

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1993

OSTI ID:7045034

Zhong, H

The Local Density Approximation (LDA) and the one-electron perturbation theory is used to compute various optical properties of semiconductors, including the dielectric function, second-harmonic-generation-coefficients, photoelastic constants (characterizing the strain-induced birefrigence) and the optical-activity tensor (describing the differences in the optical response to left-handed and right-handed circularly polarized light). The calculation of the optical activity requires perturbation theory in the vector potential in order to describe the rotation of the plane of polarization perpendicular to the direction of propagation. The author contrasts this approach with scaler-perturbation theory which can be used for the other properties computed. Self-energy effects necessary to obtain the correct band gap are included by the use of a [open quotes]scissors operator[close quotes]. In addition, local-field corrections are included in the dielectric constants and second-harmonic-generation coefficients for selenium and [alpha]-quartz and the photoelastic constants for silicon (for photon frequencies below the band gap). Good agreement (discrepancies of the order of a few percent) is obtained with the experiments. The two components of the optical-activity tensor are computed for both selenium and [alpha]-quartz in the long-wavelength limit but local-field effects have been neglected in the absence of any appropriate formalism. For both materials the computed components are consistent with frequency dependence and relative sign of the phenomenological coupled-oscillator model. For selenium, in the low-frequency range the magnitude of the optical rotatory power, one component of the tensor, is factor of two too small compared with the experiment. For [alpha]-quartz the computed components are a factor of five smaller than the reported values. The possible contributions of local-field corrections and excitonic effects are discussed.

• Research Organization: Ohio State Univ., Columbus, OH (United States)
• OSTI ID: 7045034
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
ELASTICITY
ELECTRO-OPTICAL EFFECTS
ELEMENTS
FREQUENCY MIXING
HARMONIC GENERATION
MATERIALS
MECHANICAL PROPERTIES
MINERALS
OPTICAL ACTIVITY
OPTICAL PROPERTIES
OXIDE MINERALS
PERTURBATION THEORY
PHOTOELASTICITY
PHYSICAL PROPERTIES
QUARTZ
SELENIUM
SEMICONDUCTOR MATERIALS
SEMIMETALS
SILICON
TENSILE PROPERTIES