Unitraveling-Carrier Photodiodes for Terahertz Applications

Ishibashi, Tadao; Muramoto, Y.; Yoshimatsu, Toshihide; Itô, Hiroshi

doi:10.1109/jstqe.2014.2336537

Cited by 206 publications

(98 citation statements)

References 35 publications

(48 reference statements)

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“…1 and 2 (which is called the "dipole" doping [18]) can markedly modify this profile resulting in the appearance of the "tooth" adjacent to each inner GL at the donor sheet side. The barrier doping was effectively used also in the unitravelling-carrier (UTC) photodiodes to reinforce the injection of the electrons photogenerated in the emitter of these devices [19]. The doping of the GLs can also lead shift of the Fermi level in the GLs with respect to the Dirac level.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear response of infrared photodetectors based on van der Waals heterostructures with graphene layers

Ryzhii¹,

Ryzhii²,

Svintsov³

et al. 2017

Opt. Express

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Keywords: graphene, van der Waals heterostructure, infrared photodetector. We study the operation of infrared photodetectors based on van der Waals heterostructures with the multiple graphene layers (GLs) and n-type emitter and collector contacts. The operation of such GL infrared photodetectors (GLIPs) is associated with the photoassisted escape of electrons from the GLs into the continuum states in the conduction band of the barrier layers due to the interband photon absorption, the propagation of these electrons and the electrons injected from the emitter across the heterostructure and their collection by the collector contact. The space charge of the holes trapped in the GLs provides a relatively strong injection and large photoelectric gain. We calculate the GLIP responsivity and dark current detectivity as functions of the energy of incident infrared photons and the structural parameters. It is shown that both the periodic selective doping of the inter-GL barrier layers and the GL doping lead to a pronounced variation of the GLIP spectral characteristics, particularly near the interband absorption threshold, while the doping of GLs solely results in a substantial increase in the GLIP detectivity. The doping "engineering" opens wide opportunities for the optimization of GLIPs for operation in different parts of radiation spectrum from near infrared to terahertz.

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Section: Introductionmentioning

confidence: 99%

Nonlinear response of infrared photodetectors based on van der Waals heterostructures with graphene layers

Ryzhii¹,

Ryzhii²,

Svintsov³

et al. 2017

Opt. Express

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“…3, together with the experimental data up to 110 GHz and the results obtained using the new equivalent circuit shown in Fig. 1 [3].…”

Section: Resultsmentioning

confidence: 89%

“…HOTONIC THz emitters, based on antennas integrated with UTC photodiodes [1][2][3], are promising candidates for the realisation of compact and efficient continuous-wave sources within the lower part of the THz spectrum (100 GHz -3 THz). Current research on antenna integrated UTC-PDs is focused on increasing the emitted power and bandwidth.…”

Section: Introductionmentioning

confidence: 99%

Accurate modelling and measurement of the impedance match between UTC photodiodes and THz antennas

Natrella¹,

Liu²,

Graham³

et al. 2016

2016 41st International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)

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Abstract-Maximising the power extracted from UTC photodiodes is central to the successful realisation of photonic terahertz emitters. For antenna integrated UTCs this requires the optimisation of the impedance match between UTCs and antennas. We present a comprehensive investigation of the UTC output impedance up to 400 GHz, by means of a semi-analytical approach and using 3D full-wave modelling. We introduce a new, accurate, UTC circuit model, exhibiting very good agreement with the measurements. By properly taking into account the UTC-to-antenna impedance match, we demonstrate successful prediction of the absolute level of power radiated by a bow-tie antenna integrated UTC.

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“…In this experiment, a single channel is generated by simply switching on one CW laser, but keeping the others off. In our experiment, a uni-travellingcarrier photodiode (UTC-PD) is used as a THz photo-mixing emitter, due to its extremely fast photo-response [22] [23]. Before launching into the UTC-PD, the optical signals are polarized to minimize the polarization dependency of the UTC-PD.…”

Section: Methodsmentioning

confidence: 99%