Topic
Quantum well
About: Quantum well is a research topic. Over the lifetime, 44627 publications have been published within this topic receiving 674023 citations. The topic is also known as: QW & quantum potential well.
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TL;DR: In this article, the authors summarize some of the salient properties of excitons in GaAs quantum wells and in doing so it will emphasize work at AT&T Bell Labs with which the authors have been associated.
173 citations
TL;DR: In this article, the experimental aspects of the optical properties of excitons in ZnO-based MQW heterostructures were discussed. And the binding energies of exciton and biexciton were enhanced from the bulk values, as a result of quantum-confinement effects.
Abstract: Recently the developments in the field of II?VI-oxides have been spectacular. Various epitaxial methods have been used to grow epitaxial ZnO layers. Not only epilayers but also sufficiently good-quality multiple quantum wells (MQWs) have been grown by laser molecular-beam epitaxy (laser-MBE). We mainly discuss the experimental aspect of the optical properties of excitons in ZnO-based MQW heterostructures. Systematic temperature-dependent studies of optical absorption and photoluminescence in these MQWs were used to evaluate the well-width dependence and the composition dependence of the major excitonic properties. Based on these data, the localization of excitons, the influence of exciton?phonon interaction and quantum-confined Stark effects are discussed. The optical spectra of dense excitonic systems are shown to be determined mainly by the interaction process between excitons and biexcitons. The high-density excitonic effects play a role in the observation of room-temperature stimulated emission in the ZnO MQWs. The binding energies of exciton and biexciton are enhanced from the bulk values, as a result of quantum-confinement effects.
173 citations
TL;DR: In this article, the authors achieved a high responsivity, R=1.9 A/W, 10 μm infrared detector using intersubband absorption in GaAs/AlxGa1−xAs quantum well superlattices.
Abstract: We have achieved a high responsivity, R=1.9 A/W, 10 μm infrared detector using intersubband absorption in GaAs/AlxGa1−xAs quantum well superlattices. The photocurrent is produced by intersubband absorption followed by efficient photoexcited tunneling. This responsivity is nearly four times higher than our previous results and has been obtained by using thicker and higher AlxGa1−xAs superlattice barriers thereby reducing the dark current and allowing the detector to be operated at higher biases.
173 citations
TL;DR: In this paper, the structural and optical properties of GaAs-based 1.3 μm InAs/InGaAs dots-in-a-well (DWELL) structures have been optimized in terms of different InGaAs and GaAs growth rates, the amount of InAs deposited, and In composition of the INGaAs quantum well (QW).
Abstract: The structural and optical properties of GaAs-based 1.3 μm InAs/InGaAs dots-in-a-well (DWELL) structures have been optimized in terms of different InGaAs and GaAs growth rates, the amount of InAs deposited, and In composition of the InGaAs quantum well (QW). An improvement in the optical efficiency is obtained by increasing the growth rate of the InGaAs and GaAs layers. A transition from small quantum dots (QDs), with a high density (∼5.3×1010 cm−2) and broad size distribution, to larger quantum dots with a low dot density (∼3.6×1010 cm−2) and narrow size distribution, occurs as the InAs coverage is increased from 2.6 to 2.9 monolayers. The room-temperature optical properties also improve with increased InAs coverage. A strong dependence of the QD density and the QD emission wavelength on the In composition of InGaAs well has been observed. By investigating the dependence of the dot density and the high-to-width ratio of InAs islands on the matrix of InGaAs strained buffer layer (SBL), we show that the increasing additional material from wetting layer and InGaAs layer into dots and the decreasing repulsive strain field between neighboring islands within substrate are responsible for improving QD density with increasing In composition in InGaAs SBL. The optical efficiency is sharply degraded when the InGaAs QW In composition is increased from 0.15 to 0.2. These results suggest that the optimum QW composition for 1.3 μm applications is ∼15%. Our optimum structure exhibits a room temperature emission of 1.32 μm with a linewidth of 27 meV.
173 citations
TL;DR: In this article, the binding energy of excitons in a semiconductor (e.g., GaAs) quantum well to each other and to neutral donors is calculated variationally using the six-parameter wave function of Brinkman, Rice and Bell.
Abstract: The binding energy of excitons in a semiconductor (e.g., GaAs) quantum well to each other and to neutral donors is calculated variationally using the six-parameter wave function of Brinkman, Rice, and Bell. The biexciton results for wells of various thicknesses agree closely with some of the data previously assigned to the biexciton. The biexciton binding relative to the exciton binding in the two-dimensional limit is about 3-4 times larger than in the three-dimensional case, but otherwise varies in a similar way with the mass ratio. It is found that the biexciton and bound exciton closely obey Haynes's rule.
173 citations