Optical Detection of Magnetic Resonance in Semiconductors.
Abstract
This report describes work on compound semiconductors using spin sensitive optical polarization and photoconductivity. Since the grant was awarded in February 1979 the spectrometer has been redesigned to give greater versatility and sensitivity. Some of the design features have been implemented and tested to show that theoretical advantages are indeed matched by experiment. The experiments so far attempted have been concerned with CdTe and GaAs:Cr. For CdTe, recombination luminescence following band gap excitation has been shown to be due to recombination processes involving donor states with g(D) = 1.61 and acceptors of g(A) = 1.35. The spectral dependence of these resonances show that the recombination is complex involving excitons trapped at neutral donors and neutral acceptors as well as holes trapped at neutral donors. The advantage of applying spin sensitive photoconductivity is readily apparent in experiments using band gap excitation in CdTe. When used for semi-insulating GaAs:Cr one remarkably observes the (5)T(2) ground state resonance even when excited with photons of energy less than one half the band gap energy. In fact spectral dependence of this resonance shows most of the sharp vibronic features of the (5)T(2) to (5)A(2) absorption band. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1980
- Accession Number
- ADA082629
Entities
People
- Brian Henderson
Organizations
- Trinity College Dublin