MBE growth of AlN/GaN-based photovoltaic intersubband photodetectors

We report on the molecular-beam epitaxial growth, fabrication and characterization of AlN/GaN photovoltaic quantum well infrared photodetectors operating at 1.55 µm. Devices display a spectrally-narrow photovoltaic response to p-polarized light in the near infrared at room temperature. We have analysed the effect of the growth temperature, quantum well thickness, and number of periods in the active region, concluding that responsivity is enhanced by growing at relatively low temperature and by increasing the number of quantum wells.