Engineering topics

Shchukin, V. A.

Publications and source records attributed to Shchukin, V. A..

3 records

DOE OSTI2018

A Design and New Functionality of Antiwaveguiding Vertical-Cavity Surface-Emitting Lasers for a Wavelength of 850 nm

Vertical-cavity surface-emitting lasers (VCSELs) with an aperture limited by an oxide and a resonance cavity based on GaAlAs with high Al content provide a maximum γ factor (λ/2 design) and suppression of optical power beyond the aperture. A VCSEL with two coupled cavities provides additional sharp growth of the loss of high-order lateral modes by leakage to the oxidized region and provides single-mode laser generation for an aperture diameter of up to 5 μm. Single-mode antiwaveguiding VCSELs provide ultrafast data transmission with a rate of up to 160 Gbit/s. The structure in which the active medium is placed in the lower distributed Bragg reflector and the cavity and the upper distributed Bragg reflector are dielectric, reducing the temperature shift of the radiation wavelength by a factor of 2 (to ∼0.03 nm/K).

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2014

Green (In,Ga,Al)P-GaP light-emitting diodes grown on high-index GaAs surfaces

We report on green (550–560 nm) electroluminescence (EL) from (Al{sub 0.5}Ga{sub 0.5}){sub 0.5}In{sub 0.5}P-(Al{sub 0.8}Ga{sub 0.2}){sub 0.5}In{sub 0.5}P double p-i-n heterostructures with monolayer-scale GaP insertions in the cladding layers and light-emitting diodes based thereupon. The structures are grown side-by-side on high-index and (100) GaAs substrates by molecular beam epitaxy. At moderate current densities (∼500 A/cm{sup 2}), the EL intensity of the structures is comparable for all substrate orientations. Opposite to the (100)-grown strictures, the EL spectra of (211) and (311)-grown devices are shifted towards shorter wavelengths (∼550 nm at room temperature). At high current densities (>1 kA/cm{sup 2}), a much higher EL intensity is achieved for the devices grown on high-index substrates. The integrated intensity of (311)-grown structures gradually saturates at current densities above 4 kA/cm{sup 2}, whereas no saturation is revealed for (211)-grown structures up to the current densities above 14 kA/cm{sup 2}. We attribute the effect to the surface orientation-dependent engineering of the GaP band structure, which prevents the escape of the nonequilibrium electrons into the indirect conduction band minima of the p-doped (Al{sub 0.8}Ga{sub 0.2}){sub 0.5}In{sub 0.5}P cladding layers.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2014

Morphology evolution in strain-compensated multiple quantum well structures

Morphology evolution in (In,Ga)As-Ga(As,P) strain-compensated multilayer structures is studied. The effects of nanoscale interface corrugation and phase separation are evident after the third period of the multilayer structure and become more pronounced with each new stack until the sixth period. Then, the interface stabilizes pointing to the formation of strain-balanced equilibrium interface structure. The epitaxial structure remains defect-free up to the maximum number (twenty) of periods studied. In a structure with a high lattice mismatch between the neighboring layers, In{sub 0.40}Ga{sub 0.60}As/GaAs{sub 0.85}P{sub 0.15}, clusters of dislocations are revealed already in the third period. The observed phenomena are critical for proper engineering of optoelectronic devices.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗