Intervalley shunting of electrons in modulation-doped multiple-quantum-well structures

Educato, J. L.; Leburton, Jean–Pierre; Wang, Jin; Bailey, Di

doi:10.1103/physrevb.44.8365

Cited by 19 publications

(5 citation statements)

References 20 publications

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“…In equation ( 4), α is the angle between the 3D electron wave vector and the QW plane [41]. The rates of 2D ↔ 2D and 3D ↔ 2D intervalley scatterings between and the higher lying valleys are formulated as given in [43,44].…”

Section: Scattering Ratesmentioning

confidence: 99%

Detailed investigation of electron transport, capture and gain in Al_0.3Ga_0.7As/GaAs quantum well infrared photodetectors

Cellek

Besikci

2003

Semicond. Sci. Technol.

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We present an investigation of Al 0.3 Ga 0.7 As/GaAs quantum well infrared photodetectors (QWIPs) through detailed ensemble Monte Carlo simulations. Both two-dimensional and three-dimensional electrons are simulated with realistically evaluated scattering rates. Transport of the excited electrons is accurately modelled including the reflections from well-barrier interfaces. The details incorporated into the simulator clarified some important phenomena, as well as verifying the previous predictions. Under large bias, well accumulation occurs non-uniformly, being highest near the emitter. Contrary to previous assumptions, the L valley is found to be the origin of a significant portion of the captured electrons even under typical bias voltages. -L transfer, while decreasing carrier mobility, also increases capture probability and decreases the electron lifetime, having a twofold effect on device gain. The above findings explain the large difference between the gains of Al x Ga 1−x As/GaAs (with x ∼ 0.3) and InP/In 0.53 Ga 0.47 As (or GaAs/In x Ga 1−x As) QWIPs, as well as the bias dependence of gain. The average barrier electron velocity is close to the saturated electron velocity in bulk Al 0.3 Ga 0.7 As under moderate and large bias; however, low-field mobility is significantly lower than that in bulk material. While complementing previous work, our results offer a deeper understanding of some important QWIP characteristics by resolving the details of transport and electron dynamics in the device.

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Section: Scattering Ratesmentioning

confidence: 99%

Detailed investigation of electron transport, capture and gain in Al_0.3Ga_0.7As/GaAs quantum well infrared photodetectors

Cellek

Besikci

2003

Semicond. Sci. Technol.

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“…Studies focusing on scattering and transport between different valleys without the spin degree of freedom have been performed long time ago. 28,29,30,31,32 When spin is considered, the different spin-orbit couplings and the different effective gfactors, together with the well known different momentum relaxations at different valleys may lead to complex spin R&D phenomena. Spin injection through a Schottky barrier into bulk GaAs, with Γ-L-X valley structure included, has been studied by Monte-Carlo simulation, revealing faster decay of current (electron) spin polarization in the upper valleys.…”

Section: Introductionmentioning

confidence: 99%

Multivalley spin relaxation in the presence of high in-plane electric fields inn-type GaAs quantum wells

Zhang

Zhou

2008

Phys. Rev. B

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Multi-valley spin relaxation in n-type GaAs quantum wells with in-plane electric field is investigated at high temperature by means of kinetic spin Bloch equation approach. The spin relaxation time first increases and then decreases with electric field, especially when the temperature is relatively low. We show that L valleys play the role of a "drain" of the total spin polarization due to the large spin-orbit coupling in L valleys and the strong Γ-L inter-valley scattering, and thus can enhance spin relaxation of the total system effectively when the in-plane electric field is high. Under electric field, spin precession resulting from the electric-field-induced magnetic field is observed. Meanwhile, due to the strong Γ-L inter-valley scattering as well as the strong inhomogeneous broadening in L valleys, electron spins in L valleys possess almost the same damping rate and precession frequency as those in Γ valley. This feature still holds when a finite static magnetic field is applied in Voigt configuration, despite that the g-factor of L valleys is much larger than that of Γ valley. Moreover, it is shown that the property of spin precession of the whole system is dominated by electrons in Γ valley. Temperature, magnetic field, and impurity can affect spin relaxation in low electric field regime. However, they are shown to have marginal influence in high electric field regime.

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“…It is also noted that the values of ␣ and ␤ can fit all the curves and are independent of T. The ␣ factor indicates that the scattering loss may also be attributed to the intervalley scattering. 17,18 The smaller fitting parameters in sample B may mean a smaller loss because of the thinner barrier.…”

Section: Resultsmentioning

confidence: 99%

The study of temperature dependence of photoresponse in superlattice infrared photodetectors

Wang

et al. 2007

Journal of Applied Physics

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Temperature dependence of the photoresponse in two superlattice infrared photodetectors with different single barriers is studied. It is found that the short-wavelength response decreases with temperature, but the long-wavelength one increases. The crossing point of those two response ranges is independent of temperature. The movement of its associated wavelength under different biases is investigated and analyzed. The relevant physical mechanisms are found and integrated into a simple model to explain the experimental results. Based on the model, another sample with a superlattice integrated with multiple quantum wells is designed to demonstrate whether its temperature dependence of the photoresponse is consistent with our understanding. The sample indeed shows a broadband response which enhances with temperature in all wavelengths.

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Intervalley shunting of electrons in modulation-doped multiple-quantum-well structures

Cited by 19 publications

References 20 publications

Detailed investigation of electron transport, capture and gain in Al_0.3Ga_0.7As/GaAs quantum well infrared photodetectors

Detailed investigation of electron transport, capture and gain in Al_0.3Ga_0.7As/GaAs quantum well infrared photodetectors

Multivalley spin relaxation in the presence of high in-plane electric fields inn-type GaAs quantum wells

The study of temperature dependence of photoresponse in superlattice infrared photodetectors

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Intervalley shunting of electrons in modulation-doped multiple-quantum-well structures

Cited by 19 publications

References 20 publications

Detailed investigation of electron transport, capture and gain in Al0.3Ga0.7As/GaAs quantum well infrared photodetectors

Detailed investigation of electron transport, capture and gain in Al0.3Ga0.7As/GaAs quantum well infrared photodetectors

Multivalley spin relaxation in the presence of high in-plane electric fields inn-type GaAs quantum wells

The study of temperature dependence of photoresponse in superlattice infrared photodetectors

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Product

Resources

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Detailed investigation of electron transport, capture and gain in Al_0.3Ga_0.7As/GaAs quantum well infrared photodetectors

Detailed investigation of electron transport, capture and gain in Al_0.3Ga_0.7As/GaAs quantum well infrared photodetectors