Mid-infrared sensors detect infrared radiation emitted from objects, and are actually widely used for monitoring gases and moisture as well as for imaging objects at or above room temperature. Infrared photodetectors offer fast detection, but many devices cannot provide high responsivity at room temperature. Here we demonstrate infrared sensing with high responsivity at room temperature. The central part of our device is an Al0.3Ga0.7As/GaAs heterostructure containing InAs quantum-dot (QD) layer with a 10-nm-thick GaAs spacer. In this device, the electrons that have been accumulated at the heterointerface are transferred to the conduction band of the Al0.3Ga0.7As barrier by absorbing infrared photons and the following drift due to the electric field at the interface. These intraband transitions at the heterointerface are sensitized by the QDs, suggesting that the presence of the QDs increases the strength of the intraband transition near the heterointerface. The room-temperature responsivity spectrum exhibits several peaks in the mid-infrared wavelength region, corresponding to transitions from the InAs QD and wetting layer states as well as the transition from the quantized state of the triangular potential well at the two-dimensional heterointerface. We find that the responsivity is almost independent of the temperature and the maximum value at 295 K is 0.8 A/W at ~ 6.6 µm for a bias of 1 V, where the specific detectivity is 1.8 × 10 10 cmHz1/2/W.

Murata, T., Asahi, S., Sanguinetti, S., Kita, T. (2020). Infrared photodetector sensitized by InAs quantum dots embedded near an Al0.3Ga0.7As/GaAs heterointerface. SCIENTIFIC REPORTS, 10(1) [10.1038/s41598-020-68461-w].

Infrared photodetector sensitized by InAs quantum dots embedded near an Al0.3Ga0.7As/GaAs heterointerface

Sanguinetti S.;
2020

Abstract

Mid-infrared sensors detect infrared radiation emitted from objects, and are actually widely used for monitoring gases and moisture as well as for imaging objects at or above room temperature. Infrared photodetectors offer fast detection, but many devices cannot provide high responsivity at room temperature. Here we demonstrate infrared sensing with high responsivity at room temperature. The central part of our device is an Al0.3Ga0.7As/GaAs heterostructure containing InAs quantum-dot (QD) layer with a 10-nm-thick GaAs spacer. In this device, the electrons that have been accumulated at the heterointerface are transferred to the conduction band of the Al0.3Ga0.7As barrier by absorbing infrared photons and the following drift due to the electric field at the interface. These intraband transitions at the heterointerface are sensitized by the QDs, suggesting that the presence of the QDs increases the strength of the intraband transition near the heterointerface. The room-temperature responsivity spectrum exhibits several peaks in the mid-infrared wavelength region, corresponding to transitions from the InAs QD and wetting layer states as well as the transition from the quantized state of the triangular potential well at the two-dimensional heterointerface. We find that the responsivity is almost independent of the temperature and the maximum value at 295 K is 0.8 A/W at ~ 6.6 µm for a bias of 1 V, where the specific detectivity is 1.8 × 10 10 cmHz1/2/W.
Articolo in rivista - Articolo scientifico
Infrared photodetector, quantum dot, III-V semiconductors;
English
15-lug-2020
2020
10
1
11628
none
Murata, T., Asahi, S., Sanguinetti, S., Kita, T. (2020). Infrared photodetector sensitized by InAs quantum dots embedded near an Al0.3Ga0.7As/GaAs heterointerface. SCIENTIFIC REPORTS, 10(1) [10.1038/s41598-020-68461-w].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/319692
Citazioni
  • Scopus 20
  • ???jsp.display-item.citation.isi??? 16
Social impact