title: Voltage-tunable dual-band quantum dot infrared photodetectors for temperature sensing.
abstract: We report voltage-tunable 3-5 μm & 8-12 μm dual-band detection in the InAs/Al0.3Ga0.7As/In0.15Ga0.85As confinement-enhanced dots-in-a-well quantum dot infrared photodetectors. The capability in temperature sensing is also demonstrated. Distinct response peaks at 5.0 μm and 8.6 μm were observed in the photocurrent spectra with working temperature up to 140K. The two peaks correspond to the transition paths from the quantum dot ground state to the quantum well state and the quantum dot excited state, respectively. At 77K, the response ratio of the 8.6 μm peak over the 5.0 μm peak changes from 0.29 at -3V to 5.8 at + 4.8V. Excellent selectivity between the two peaks with bias voltage makes the device attractive for third-generation imaging systems with pixel-level multicolor functionality.
authors.affiliation: Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan.
authors.forename: Hong-Shi
authors.initials: HS
authors.lastname: Ling
authors.forename: Shiang-Yu
authors.initials: SY
authors.lastname: Wang
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: Hsu
authors.forename: Chien-Ping
authors.initials: CP
authors.lastname: Lee
mesh_terms: D000535:Aluminum / Q000737:chemistry; D001152:Arsenicals / Q000737:chemistry; D005708:Gallium / Q000737:chemistry; D007204:Indium / Q000737:chemistry; D007259:Infrared Rays; D008027:Light; D018625:Microscopy, Atomic Force / Q000379:methods; D036103:Nanotechnology / Q000379:methods*; D055095:Optics and Photonics; D010777:Photochemistry / Q000379:methods*; D045663:Quantum Dots; D013696:Temperature
chemical_list: D001152:Arsenicals; D007204:Indium; C043055:gallium arsenide; D005708:Gallium; D000535:Aluminum; C076773:indium arsenide