Optical properties of CdTe/Cd[sub 1-x]Zn[sub x]Te strained-layer single quantum wells
The electronic states in a series of molecular-beam-epitaxy-grown CdTe/Cd[sub 1[minus]x]Zn[sub x]Te strained-layer single quantum wells are studied. The confined states were calculated using the three-band envelope function model taking into account the strain effect. Calculation based on model solid theory and deformation potential theory shows that, at Zn concentration of 0.21, the band lineup is type I for heavy holes and type II for light holes. An interpolation scheme is developed for the parameters in ternary semiconductors. Based on the quasi cubic model description of the [Gamma]-point band structure of zinc-blend and wurtzite structure materials, a relation between the valence band edges in these two different structures is given. Photoluminescence measurement between 9.0 and 100.0 K indicates that the broadening mechanism is dominated by the polar optical phonon interactions. The circularly polarized excitation spectra show predominant heavy hole features. With well width between 25 and 75[angstrom], this study shows that exciton binding energy decreases with increasing well width. A computerized setup for optical polarization measurement is presented. The heart of this setup consists of a photoelastic modulator (PEM) whose retardation phase can be kept constant even when the wavelength of modulated light is scanned over a wide range, and a dual channel gated photon counter which can compensate the variation of excitation intensity with time and wavelength. Unlike conventional lock-in or other analog setups, where the difference of two perpendicularly polarized light components (AC) and the average of these components (DC) are extracted electronically and the ratio AC/DC is recorded as degree of polarization, this spectropolarimeter directly records the [sigma][sup +] and [sigma][sup [minus]] components or I[parallel] and I[perpendicular] components of the analyzed light signal in the same run of wavelength, temperature, etc.
- Research Organization:
- Ohio Univ., Athens, OH (United States)
- OSTI ID:
- 6975723
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Diode laser cooling of a potassium beam through a mirrored slit
Exciton binding energies and the valence-band offset in mixed type-I--type-II strained-layer superlattices
Related Subjects
CADMIUM TELLURIDES
ELECTRONIC STRUCTURE
OPTICAL PROPERTIES
ZINC TELLURIDES
BAND THEORY
INTERMETALLIC COMPOUNDS
POLARIZATION
POTENTIALS
SEMICONDUCTOR MATERIALS
ALLOYS
CADMIUM COMPOUNDS
CHALCOGENIDES
MATERIALS
PHYSICAL PROPERTIES
TELLURIDES
TELLURIUM COMPOUNDS
ZINC COMPOUNDS
360606* - Other Materials- Physical Properties- (1992-)