In the single band model, also known as the parabolic effective mass model, intersubband transitions in quantum wells (QWs) are discrete. In practice, electron-electron interaction, QW width nonuniformity, electron interactions with rough interfaces and with impurities and their enhancement by electric fields, and the optical and acoustic phonons contribute to the experimentally observed linewidth of intersubband transition in QWs.1-5 There have been quite a few theoretical reports to explain the ...
Analyzing the photocurrent spectra and the I-V characteristics of weakly coupled GaAs/AlGaAs multiquantum well structures, different transport regimes are distinguished. At low temperatures (below ~50 K), due to the electron coherence over a few periods of the superlattice, electron transport is dominated by sequential resonant tunneling. At higher temperatures, evidences for the increased contribution of nonresonant transport processes, and the subsequent modification in the electric field distribution in the device, ...
An observation of quantum interference effect in photocurrent spectra of a weakly coupled bound-to-continuum multiple quantum well photodetector is reported. This effect persists even at high biases where the Kronig Penney minibands of periodic superlattice potential in the continuum are destroyed. Our results show that electrons remain coherent over a distance of 40 50 nm. The observation was used to investigate electric field domain formation induced by sequential resonant tunneling ...
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