Excitons in semiconducting superlattices, quantum wells, and ternary alloys
- Dartmouth Coll., Hanover, NH (United States). Dept. of Physics
- Bellcore, Red Bank, NJ (United States)
Semiconducting layered structures can now be fabricated with precisely defined layer thicknesses down to one monolayer. An example is the superlattice'' (SL) structure, in which to semiconductors with different band gaps are interleaved. The electronic and optical properties of the SL are quite different from those of the constitutents and offer interesting new possibilities both in device design and in basic physics. This proposal aims to improve our understanding of optically excited states in SL's, particularly in the so-called Type 2 indirect'' SL's in which in electron and hole created by optical excitation are separated both in real and in momentum space. We study these structures by time-resolved tunable laser spectroscopy, with and without external perturbations such as magnetic field, electric field, and uniaxial stress. In SLs with only a few atomic layers per period the familiar effective mass model'' of semiconductor states breaks down. We have made precise optical experiments on well-characterized material to test current first principles'' calculations of the band structure. Our work under this grant has shown that the material we are using is of sufficiently high quality to test the theoretical predictions. Comparison of theory and experiment provides a new and sensitive probe of the interface quality on a fine scale. Statistical analysis of the temperature dependence of the exciton decay dynamics provides complementary information. From a careful study of the exciton spectra of the recently discovered mixed type 1- type 2 CdTe/CdZnTe SLs we have obtained the band offset at the CdTe/CdZnTe interface to unprecedented accuracy.
- Research Organization:
- Dartmouth Coll., Hanover, NH (United States). Dept. of Physics
- Sponsoring Organization:
- DOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG02-87ER45330
- OSTI ID:
- 5228284
- Report Number(s):
- DOE/ER/45330-5; ON: DE92015178
- Country of Publication:
- United States
- Language:
- English
Similar Records
Excitons in semiconducting superlattices, quantum wells, and ternary alloys. Performance report, September 15, 1987--January 31, 1994
Excitons in semiconducting superlattices, quantum wells, and ternary alloys
Related Subjects
360602* -- Other Materials-- Structure & Phase Studies
360606 -- Other Materials-- Physical Properties-- (1992-)
ALLOY SYSTEMS
ALUMINIUM ARSENIDES
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
CADMIUM COMPOUNDS
CADMIUM TELLURIDES
CHALCOGENIDES
CONTROL
DOCUMENT TYPES
EPITAXY
EXCITONS
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
INTERFACES
MATERIALS
MOLECULAR BEAM EPITAXY
PNICTIDES
PROGRESS REPORT
QUALITY CONTROL
QUASI PARTICLES
SEMICONDUCTOR MATERIALS
SPECTROSCOPY
SUPERLATTICES
TELLURIDES
TELLURIUM COMPOUNDS
TEMPERATURE DEPENDENCE
TERNARY ALLOY SYSTEMS
ZINC COMPOUNDS
ZINC TELLURIDES