A GaN/AlN quantum cascade detector with a broad response from the mid-infrared (4.1 μm) to the visible (550 nm) spectral range

Research paper by P. Quach, S. F. Liu, A. Jollivet, D. Wang, J. Y. Cheng, N. Isac, S. Pirotta, D. Bouville, S. S. Sheng, A. Imran, L. Chen, D. Li, X. T. Zheng, Y. X. Wang, Z. X. Qin, et al.

Indexed on: 01 May '20Published on: 27 Apr '20Published in: Applied physics letters


Applied Physics Letters, Volume 116, Issue 17, April 2020. We report on a GaN/AlN quantum cascade detector operating in an extended spectral range going from the mid-infrared to visible wavelengths. This broadband detection is achieved thanks to the design of active quantum wells supporting five bound-to-bound intersubband transitions. The photodetector exhibits a broad signal between 4.1 μm and 550 nm. The photocurrent persists up to room temperature. The calibrated responsivity at 77 K under irradiation through a 45° angle polished facet amounts to 7 μA/W at a wavelength of 633 nm and is peaked at 14 μA/W at a wavelength of 720 nm.