Quantum well infrared photodetector

A Quantum Well Infrared Photodetector (QWIP) is an infrared photodetector, which uses electronic intersubband transitions in quantum wells to absorb photons. In order to be used for infrared detection, the parameters of the quantum wells in the quantum well infrared photodetector are adjusted so that the energy difference between its first and second quantized states match the incoming infrared photon energy. QWIPs are typically made of gallium arsenide, a material commonly found in smartphones and high-speed communications equipment. Depending on the material and the design of the quantum wells, the energy levels of the QWIP can be tailored to absorb radiation in the infrared region from 3 to 20 µm.

QWIPs are one of the simplest quantum mechanical device structures that can detect mid-wavelength and long-wavelength infrared radiation. They are known for their stability, high pixel-to-pixel uniformity, and high-pixel operability.