InGaAsGaAs

InGaAsGaAs refers to a family of heterostructures and alloy systems that combine indium gallium arsenide, InxGa1−xAs, with gallium arsenide, GaAs. The indium content x allows tuning of the lattice constant and the electronic band structure, enabling control over optical and electronic properties. When grown on GaAs substrates or buffers, the InGaAs layer is typically strained to match the underlying lattice, with the degree of strain depending on composition and layer thickness.

Composition and structure are governed by the mixture of indium and gallium and the resulting lattice mismatch with GaAs. Increasing indium content lowers the direct bandgap of InGaAs and shifts its absorption and emission toward longer wavelengths. Lattice mismatch introduces strain, which can be used to tailor electronic states in quantum wells, but excessive strain may cause dislocations if the layer exceeds its critical thickness.

Growth methods for InGaAs on GaAs include molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD). These techniques offer precise control over composition and thickness, essential for achieving desired bandgaps and strain profiles. Device performance is sensitive to interface quality and defect density, making careful growth and post-growth processing important.

Applications of InGaAsGaAs structures span optoelectronics and high-speed electronics. They are used in infrared photodetectors and lasers, modulators, and heterojunction devices that leverage the tunable bandgap and high carrier mobility of the InGaAs/GaAs system. Integration with GaAs-based circuits supports compact, wavelength-tuned components for communications and sensing.

See also: III-V semiconductors, GaAs, InAs, InGaAs, quantum wells, lattice mismatch, MBE, MOCVD.