Resonant cavity light-emitting diodeE. F. Schubert, Y.-H. Wang, A. Y. Cho et al.|Applied Physics Letters|1992 A novel concept of a light-emitting diode (LED) is proposed and demonstrated in which the active region of the device is placed in a resonant optical cavity. As a consequence, the optical emission from the active region is restricted to the modes of the cavity. Resonant cavity light-emitting diodes (RCLED) have higher spectral purity and higher emission intensity as compared to conventional light emitting diodes. Results on a top-emitting RCLED structure with AlAs/AlxGa1−xAs quarter wave mirrors grown by molecular beam epitaxy are presented. The experimental emission linewidth is 17 meV (0.65 kT) at room temperature. The top-emission intensity is a factor of 1.7 higher as compared to conventional LEDs.
Drastic reduction of series resistance in doped semiconductor distributed Bragg reflectors for surface-emitting lasersK. Tai, Long Yang, Y. H. Wang et al.|Applied Physics Letters|1990 Modifications to reduce the series resistance in p-type semiconductor distributed Bragg reflectors (DBR) consisting of ten pairs of quarter-wavelength GaAs (high refractive index)/Al0.7Ga0.3As (low index) layers were made by inserting an intermediate Al0.35Ga0.65As layer or a 200 Å superlattice of GaAs(10 Å)/Al0.7Ga0.3As (10 Å) at the GaAs/Al0.7Ga0.3As heterointerfaces. The specific DBR series resistance was reduced by two orders of magnitude to about 6.2×10−5 Ω cm2. These modifications did not alter the optical reflectivity and nearly identical reflection spectra were measured.
Observation of Magnetophonon Resonances in a Two-Dimensional Electronic SystemD. C. Tsui, Th. Englert, A. Y. Cho et al.|Physical Review Letters|1980 We report the first observation of magnetophonon resonances in the two-dimensional electronic system in single interface GaAs-${\mathrm{Al}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}$ heterojunctions and heterojunction superlattices. They result from inelastic scattering between Landau levels with resonant absorption of LO phonons of GaAs and yield a polaron mass ${{m}_{p}}^{*}=(0.077\ifmmode\pm\else\textpm\fi{}0.004){m}_{e}$.
Alloy Clustering in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Ga</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Al</mml:mi></mml:mrow><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mi mathvariant="normal">As</mml:mi></mml:math>Compound Semiconductors Grown by Molecular Beam EpitaxyP. M. Petroff, A. Y. Cho, F. K. Reinhart et al.|Physical Review Letters|1982 Direct evidence of alloy clustering in the ${\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Al}}_{x}\mathrm{As}$ alloy system is presented. Clustering is observed only on the nonpolar surface of GaAs. An exchange reaction model is proposed to account for the existence of a surface-orientation-dependent miscibility gap for this alloy system.
Raman scattering in superlattices: Anisotropy of polar phononsR. Merlín, C. Colvard, M. V. Klein et al.|Applied Physics Letters|1980 Raman experiments on polar phonons in GaAs-Ga1−xAlxAs superlattices are reported. Other data from the literature, and its interpretation in terms of folding of the phonon Brillouin zone and scattering from q≠0 phonons induced by electronic zone folding, are discussed. An alternative explanation is presented based on optical anisotropy induced by layering. Numerical results show good agreement with experiment.