Båndgabsingeniøring

Båndgabsingeniøring, or band-gap engineering, is the deliberate modification of a material's electronic band gap to control its electrical and optical properties. By tuning the energy difference between the valence and conduction bands, engineers can adjust absorption spectra, emission wavelengths, and carrier dynamics, enabling devices across electronics and photonics.

Techniques used in båndgabsingeniøring include alloying and composition control, where changing the relative amounts of elements shifts the band gap (for example in AlxGa1−xAs or InxGa1−xN). Quantum confinement in thin films, quantum wells, wires, and dots also alters the effective gap. Strain engineering through lattice mismatch can modify band-edge positions, and heterostructures with tailored band offsets enable targeted carrier confinement. In some materials, external fields or controlled doping provide additional means to adjust band structure.

Materials and platforms commonly involved include silicon-based systems such as SiGe alloys for lattice-matched modifications, III–V semiconductors like GaAs/AlGaAs and InP-based compounds, and emerging materials such as hybrid perovskites and two-dimensional materials where dimensionality strongly affects the band gap. The choice of material and structure depends on the desired device function and operating wavelength.

Applications of båndgabsingeniøring span LEDs and laser diodes with specific wavelengths, photovoltaic cells optimized for particular spectra, photodetectors, and high-performance transistors. Integrated optoelectronics rely on engineered band gaps to align electronic and photonic components and improve efficiency.

Historical development began with concepts like quantum wells and heterostructures in the late 20th century, expanding the design space for semiconductor devices. Ongoing challenges include defect control, thermal stability, and scalable manufacturing.