| Hydrostatic pressure studies on metalorganic chemical vapor deposition (MO-CVD) grown Al(,x)Ga(,1-x)As-GaAs quantum-well heterostructure (QWH) laser diodes and on AlAs-GaAs and Al(,x)Ga(,1-x)As-GaAs superlattices (SL's) are described. The growth and characterization of visible-light emitting In(,1-x)Ga(,x)P-In(,1-x)Ga(,x)P(,1-z)As(,z) heterostructures grown on GaAs(,1-y)P(,y) substrates are discussed.;Al(,x)Ga(,1-x)As-GaAs QWH laser diodes grown by MO-CVD are examined in emission under hydrostatic pressure. The pressure coefficient at low pressure is shown to be approximately the same as for the SL's ((TURN) 11.5 meV/kbar). A size-dependent (layer thickness) break in the pressure coefficient to (TURN) 8.5 meV/kbar at higher pressures is noted. This discontinuity in pressure coefficients is attributed to the effect of shear stresses generated within the bulk p- and n-doped confining and contact layers (when subjected to external hydrostatic pressure) on the relative movement of the heavy- and light-hole subbands.;Visible-light emitting In(,1-x)Ga(,x)P-In(,1-x)Ga(,x)P(,1-z)As(,z) heterostructure platelet lasers capable of operating continuously at room temperature (cw, 300 K; (lamda)(TURN) 6700 (ANGSTROM)) are described. These platelet lasers demonstrate the highest energy cw 300 K laser operation of any semiconductor yet reported. The liquid phase epitaxial (LPE) growth of these heterostructures is discussed. Limitations imposed by the LPE growth kinetics and the presence of substrate defects also are addressed.;Optical absorption experiments on MO-CVD AlAs-GaAs and Al(,x)Ga(,1-x)As-GaAs SL's subjected to hydrostatic pressure enable the simultaneous measurement of pressure coefficients not only near the (GAMMA)-conduction band edge, but also on confined-particle states high into the band (above the L- and possibly the X-indirect minima). The pressure coefficients measured for the confined-particle states are all the same ((TURN) 11.5 meV/kbar). This indicates that with the lattice deformation associated with hydrostatic pressure, the (GAMMA)-minimum retains its "shape" (i.e., parabolicity) high into the band. The effect of the X-indirect minima on the confined-particle state ((GAMMA)-related) absorption is greater than that observed from the L-indirect minima. This is attributed to the differences in density of states in the indirect minima. The measured pressure coefficient for these SL's of (TURN) 11.5 meV/kbar is shown to differ from that of bulk GaAs. This difference is discussed with regard to effects of the thin layers on the deformation potential constants of the SL's. |
