Magnetic-field tunable terahertz quantum well infrared photodetector

Savić, Ivana; Milanović, V.; Vukmirović, Nenad; Jovanović, V. D.; Ikonić, Z.; Indjin, D.; Harrison, P.

doi:10.1063/1.2085309

Cited by 17 publications

(12 citation statements)

References 48 publications

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“…From the steady-state solution of the system of rate equations, the population of the energy levels within the dots and in the surrounding discretised continuum were found, in a method similar to our simulations of quantum well infrared photodetectors [16,45]. Combining these population densities with lifetimes allowed the current density to be calculated.…”

Section: Rate Equations Versus Experiments In Quantum Dot Infrared Phomentioning

confidence: 99%

On the coherence/incoherence of electron transport in semiconductor heterostructure optoelectronic devices

et al. 2008

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This paper compares and contrasts different theoretical approaches based on incoherent electron scattering transport with experimental measurements of optoelectronic devices formed from semiconductor heterostructures. The Monte Carlo method which makes no a priori assumptions about the carrier distribution in momentum or phase space is compared with less computationally demanding energy-balance rate equation models which assume thermalised carrier distributions. It is shown that the two approaches produce qualitatively similar results for hole transport in p-type Si 1−x Ge x /Si superlattices designed for terahertz emission. The good agreement of the predictions of rate equation calculations with experimental measurements of mid-and far-infrared quantum cascade lasers, quantum well infrared photodetectors and quantum dot infrared photodetectors substantiate the assumption of incoherent scattering dominating the transport in these quantum well based devices. However, the paper goes on to consider the possibility of coherent transport through the density matrix method and suggests an experiment that could allow coherent and incoherent transport to be distinguished from each other.

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Section: Rate Equations Versus Experiments In Quantum Dot Infrared Phomentioning

confidence: 99%

On the coherence/incoherence of electron transport in semiconductor heterostructure optoelectronic devices

et al. 2008

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“…Further development of the growth technology of dilute magnetic semiconductors (DMSs) [5] should enable implementation of similar intraband devices based upon them. The predictions of a large tunability of intraband transition energies and significant absorption/responsivity in THz DMS quantum wells (QWs)/quantum well infrared photodetectors [6,7] promote the idea of utilizing DMSs for tunable THz QCLs.In this paper, a design of a magnetically tunable THz QCL based on ZnMnSe/ZnMgSe is proposed, emitting in the region of 2.4 − 6.3 THz and 9.2 − 10.1 THz, corresponding to active laser levels transitions of 10 − 26 meV and 38 − 42 meV. Furthermore, the analysis of the possibility of achieving population inversion is presented, and the output characteristics of the designed QCL are calculated.…”

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confidence: 99%

“…Therefore, for a fixed magnetic field, each spin requires a different electric field to achieve the alignment. The envelope function Schrödinger equation within the effective mass approximation, including the spin-dependent potential induced by magnetic field, was used to calculate the electronic structure of DMS QCLs [6,7]. The Boltzmann model of electron transport in quantum cascade structures in a magnetic field was employed to calculate the population dynamics of the LLs [7,8].…”

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confidence: 99%

Lasing in spin‐polarized terahertz quantum cascade structures

Savić

Ikonić

Vukmirović

et al. 2006

Phys. Status Solidi (c)

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We investigate theoretically the possibility of lasing in the terahertz in a suitably designed quantum cascade structure comprising dilute magnetic semiconductors. quantum cascade laser. Tunability is based on the spin-dependent potential induced by a magnetic field. The Boltzmann equation approach was used in order to predict the dependence of the gain and current on magnetic and electric fields. The electron dynamics were modeled by taking electron-longitudinal optical phonon, electron-longitudinal acoustic phonon and electron-electron scattering into account. Tunability of the emission energy between 10 meV and 26 meV, and 38 meV and 42 meV, for transitions of spin-down and spin-up electrons respectively, may be achieved by varying a magnetic field up to 5 T, at a temperature of 1.5 K. Comparison of the calculated optical gain, and losses in the appropriate waveguide, indicates the prospect of achieving laser operation.1 Introduction The development of quantum cascade lasers (QCLs) in the terahertz (THz) spectral range has attracted a lot of research interest, due to a variety of applications in spectroscopy, imaging and biomedicine. In QCLs, light emission occurs in transitions between subbands in the conduction band, or between Landau levels (LLs) stemming from them under an external magnetic field applied parallel to the growth axis. This makes the emission wavelength independent from the material system used and has made the THz range accessible with well-established semiconductor materials such as GaAs/AlGaAs [1][2][3] and InGaAs/AlInAs grown on InP [4]. Further development of the growth technology of dilute magnetic semiconductors (DMSs) [5] should enable implementation of similar intraband devices based upon them. The predictions of a large tunability of intraband transition energies and significant absorption/responsivity in THz DMS quantum wells (QWs)/quantum well infrared photodetectors [6,7] promote the idea of utilizing DMSs for tunable THz QCLs.In this paper, a design of a magnetically tunable THz QCL based on ZnMnSe/ZnMgSe is proposed, emitting in the region of 2.4 − 6.3 THz and 9.2 − 10.1 THz, corresponding to active laser levels transitions of 10 − 26 meV and 38 − 42 meV. Furthermore, the analysis of the possibility of achieving population inversion is presented, and the output characteristics of the designed QCL are calculated.

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“…The states assigned to the central period are obtained by solving the Hamiltonian eigenvalue problem in the region of space in the shape of cylinder of large radius R t containing 2N + 1 periods in the z−direction (central period, N periods to the left and N periods to the right) and selecting only the eigenstates whose probability of finding a carrier in the central period is larger than in any of the other 2N periods. In the calculations, a value of N = 2 was taken based on large value of superlattice period compared to quantum dot size and previous experience with simulations of quantum well infrared photodetectors [11,12].…”

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confidence: 99%

Theoretical modelling of electron transport in InAs/GaAs quantum dot superlattices

Vukmirović

Ikonić

Savić

et al. 2006

Phys. Status Solidi (c)

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A theoretical model describing the electron transport in InAs/GaAs quantum dot infrared photodetectors, modelled as ideal quantum dot superlattices, is presented. The carrier wave functions and energy levels were evaluated using the strain dependent 8-band k · p Hamiltonian and used to calculate all intra-and inter-period transition rates due to interaction with phonons and electromagnetic radiation. The interaction with longitudinal acoustic phonons and electromagnetic radiation was treated perturbatively within the framework of Fermi's golden rule, while the interaction with longitudinal optical phonons was considered taking into account their strong coupling to electrons. The populations of energy levels were then found from a system of rate equations, and the electron current in the superlattice was subsequently extracted.1 Introduction Considerable research effort has recently been put in the development of quantum dot infrared photodetectors [1][2][3][4][5][6][7] (QDIPs) to overcome the limitations of quantum well based devices, which has lead to a recent demonstration of QDIPs operating at room temperature [8]. On the other hand, there has been much less work on theoretical modelling of carrier transport in QDIPs [9,10]. In these models, the current is deduced from the analysis of the processes of carrier capture, thermal escape and photoexcitation. However, none of these models aims to predict the dependence of relevant QDIP output parameters, such as responsivity or dark current on the choice of material system used or on quantum dot size and composition, which it is highly desirable to know in order to optimize QDIP characteristics. Deeper understanding of underlying QDIP physics can also be achieved by obtaining information about carrier distribution among various quantum dot and continuum energy levels, which is hard to access experimentally. In this work, we therefore present a theoretical model of vertical electron transport in quantum dot infrared photodetectors, modelled as ideal quantum dot superlattices. The model being able to treat both the transport in dark and light conditions will be presented and the results of the simulation of the transport in dark conditions will be given.

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Magnetic-field tunable terahertz quantum well infrared photodetector

Abstract: Article:Savic, I., Milanovic, V., Vukmirovic, N. et

Cited by 17 publications

References 48 publications

On the coherence/incoherence of electron transport in semiconductor heterostructure optoelectronic devices

On the coherence/incoherence of electron transport in semiconductor heterostructure optoelectronic devices

Lasing in spin‐polarized terahertz quantum cascade structures

Theoretical modelling of electron transport in InAs/GaAs quantum dot superlattices

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