GaAsPbased

GaAsP-based materials refer to ternary III-V semiconductors in the gallium–arsenide–phosphide family, with the chemical composition GaAs1−xPx. They form in the zinc blende crystal structure and are typically grown as alloys on GaAs substrates. By varying the phosphorus content x, the material’s electronic properties, including the bandgap and lattice constant, can be tuned over a wide range.

The bandgap of GaAsP increases with phosphorus incorporation, allowing emission and absorption across the near-infrared to visible spectrum. GaAs itself has a direct bandgap of about 1.42 eV, while higher P content pushes the bandgap higher toward values near GaP. The lattice constant also decreases as phosphorus content increases, influencing strain and defect formation when grown on GaAs or other substrates. The direct nature of the bandgap and the ability to engineer quantum wells and superlattices make GaAsP-based structures attractive for optoelectronic devices.

Growth and fabrication are typically performed using standard III-V epitaxy methods, such as metal-organic chemical vapor deposition (MOCVD or MOVPE) and molecular beam epitaxy (MBE). Precise control of composition and thickness enables the creation of GaAsP quantum wells, p–n junctions, and heterostructures integrated with GaAs-based devices. Doping with n-type or p-type dopants allows the formation of laser diodes, light-emitting diodes, and photodetectors.

Common applications include infrared and red LEDs and laser diodes, high-efficiency photodetectors, and components in multi-junction solar cells where GaAsP layers contribute to spectral coverage. Challenges include managing lattice mismatch and defect densities at higher phosphorus contents to maintain device performance.