III-V based high-performance photodetectors in the non-visible regime - from UV to IR

Photodetectors for the non-visible region of the electromagnetic spectrum are vital for security, defense and space as well as industrial and scientific applications. The research activities at Fraunhofer IAF contribute to Europe’s non-dependence on critical components and support the European strategy for critical space technologies. A broad range of III-V material systems is developed to address the spectral region adjacent to the visible regime. For the ultraviolet (UV) spectral region, AlGaN is the material of choice with an adjustable bandgap between 3.4 and 6.0 eV, depending on the Al content, addressing the wavelength regime between 365 to 210 nm. The short-wavelength infrared (SWIR) region from 0.9 up to 3.0 μm is covered by two approaches: Lattice matched InGaAs absorber material on InP substrates for a cut-off wavelength at 1.7 μm and InGaAsSb lattice matched on GaSb substrates for 1.7 up to 3.0 μm. Through the choice of appropriate layer thickness, InAs/(In,Ga)(As,Sb) type-II superlattices (T2SLs) can be tailored to cover the wavelength range from mid- to long- up to very-long-wavelength infrared (MWIR, LWIR, VLWIR) in the spectrum of 3-15 μm.