Growth and characterization of AlInN/GaInN quantum wells for high-speed intersubband devices at telecommunication wavelengths

We report on the 1.5 μm intersubband absorption measured on GaInN multi-quantum wells with AlInN barriers grown by RF plasma assisted molecular beam epitaxy (PAMBE). The intersubband light absorption was demonstrated as a function of the well width (1.3 nm - 3 nm) at the wavelength 1.4μm - 2.5 μm. The use AlInN barriers allowed to achieve strain compensated and crack free structures on GaN substrates. The preformed XRD mapping of a and c lattice constants show that AlInN/GaInN MQWs are fully strained and have up to 7% of indium in the barriers. The replacement of AlGaN by AlInN barriers opens new possibility to grow strain compensated crack free intersubband based devices like electooptical modulators and switches operating at telecommunication wavelengths.