Unusual optical properties of type-II<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi mathvariant="normal">In</mml:mi><mml:mi mathvariant="normal">As</mml:mi><mml:mo>∕</mml:mo><mml:mi mathvariant="normal">Ga</mml:mi><mml:msub><mml:mi mathvariant="normal">As</mml:mi><mml:mn>0.7</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">Sb</mml:mi><mml:mn>0.3</mml:mn></mml:msub></mml:mrow></mml:math>quantum dots by photoluminescence studies

Chen, T. T.; Cheng, Chien‐Chuan; Chen, Y. F.; Chang, Fu−Yu; Lin, Hao‐Hsiung; Wu, C. T.; Chen, Chi-Hung

doi:10.1103/physrevb.75.033310

Cited by 41 publications

(23 citation statements)

References 18 publications

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“…Several approaches have been explored in order to achieve polarization-insensitive emission from QDs, including covering the QDs with a strain reducing layer, 5 growing multiple electronically coupled layers of QDs [6][7][8] and columnar QDs, 9,10 and forming a type-II band alignment using GaAsSb barriers. 11 However, to date, there has not been much theoretical guidance available to help people fully understand the optical properties of these QDs. Previous theoretical work 9,12 has explored the properties of columnar QDs using the kp method, which ignores atomistic granularity.…”

Section: Introductionmentioning

confidence: 99%

Experimental and theoretical study of polarization-dependent optical transitions in InAs quantum dots at telecommunication-wavelengths (1300-1500 nm)

Usman

Heck

Clarke

et al. 2011

Journal of Applied Physics

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The design of some optical devices such as semiconductor optical amplifiers for telecommunication applications requires polarization-insensitive optical emission at the long wavelengths (1300-1550 nm). Self-assembled InAs/GaAs quantum dots (QDs) typically exhibit ground state optical emission at wavelengths shorter than 1300 nm with highly polarization-sensitive characteristics, although this can be modified by using low growth rates, the incorporation of strainreducing capping layers or growth of closely-stacked QD layers. Exploiting the strain interactions between closely stacked QD layers also allows greater freedom in the choice of growth conditions for the upper layers, so that both a significant extension in their emission wavelength and an improved polarization response can be achieved due to modification of the QD size, strain and composition. In this paper we investigate the polarization behavior of single and stacked QD layers using room temperature sub-lasing-threshold electroluminescence and photovoltage measurements as well as atomistic modeling with the NEMO 3-D simulator. A reduction is observed in the ratio of the transverse electric (TE) to transverse magnetic (TM) optical mode response for a GaAs-capped QD stack compared to a single QD layer, but when the second layer of the two-layer stack is InGaAs-capped an increase in the TE/TM ratio is observed, in contrast to recent reports for single QD layers.

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Section: Introductionmentioning

confidence: 99%

Experimental and theoretical study of polarization-dependent optical transitions in InAs quantum dots at telecommunication-wavelengths (1300-1500 nm)

Usman

Heck

Clarke

et al. 2011

Journal of Applied Physics

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“…3b shows that for type-II system the periods of FKOs were broadened with increase of I ex . It means that the F also increases because confined carriers induce the localized field due to the band bending effect caused by the spatially separated photo-excited carriers in type-II alignment [5,6].…”

Section: Resultsmentioning

confidence: 99%

“…In order to analyze the tendency of F , we consider the electric field induced by photo-excited carriers. The strong localized carriers near the interface form a charged plane and, correspondingly, produce an approximately triangular well with an electric-field strength of [5,6]:…”

Section: Resultsmentioning

confidence: 99%

“…In this type-II system, optical properties have been studied in many groups using photoluminescence (PL) measurements [5,6]. It shows that a significant blue-shift of the peak energy occurs under a moderate excitation power, which can be well explained by the band bending effect due to the spatially separated photo-excited carrier in type-II band alignment.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, the separated charges by the band bending effect also induces localized electric field (F ). This F can be calculated by using theory of approximate triangular well [5,6]. However, it is difficult and complicated to obtain the value of F experimentally.…”

Section: Introductionmentioning

confidence: 99%

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Investigation of Localized Electric Field in the Type-II InAs/GaAsSb/GaAs Structure

et al. 2016

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The effect of localized electric field (F ) was investigated in the type-II InAs/GaAsSb/GaAs structures. To compare type-I to type-II, two types of samples with different Sb contents was grown by molecular beam epitaxy, whose Sb contents are 3% (type-I) and 16% (type-II), respectively. In the both samples, we performed excitation power dependent-photoreflectance at 10 K and the result showed that the period of the Franz-Keldysh oscillation, revealed above the band gap (Eg) of GaAs, was broadened in the only type-II system, which means that F was also increased because it is proportional to the period of the Franz-Keldysh oscillation while the period of the Franz-Keldysh oscillations stayed unchanged in type-I system. This phenomenon is explained by that the F was affected by the band bending effect caused by the spatially separated photo-excited carriers in the interface between GaAsSb and GaAs. The F changed linearly as a function of square root of excitation power as expected for the F . Moreover, F was calculated using fast Fourier transform method for a qualitative analysis, which is in a good agreement with the theory of triangular well approximation.

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Transient band‐bending in InP/InAs/InP core‐multishell nanowires

Goto

Tomimoto

Pal

et al. 2008

Phys. Status Solidi (c)

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We report on the photoluminescence (PL) and time‐resolved PL (TR‐PL) spectroscopy of wurtzite InP/InAs/InP core‐multishell nanowires. Multiple peaks appeared in the PL spectra due to monolayer variation of InAs layers and each PL peak showed a blueshift with a cube‐root dependence on the excitation power. This blueshift results from the band‐bending in the type‐II band configuration. Fast decay caused by the relaxation of the band‐bending was observed at higher energy sides of the PL peaks in the TR‐PL measurement. The blueshift calculated by a triangular quantum well approximation in type‐II configuration was in good agreement with that observed in the experiment. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Unusual optical properties of type-IIInAs∕GaAs0.7Sb0.3quantum dots by photoluminescence studies

Cited by 41 publications

References 18 publications

Experimental and theoretical study of polarization-dependent optical transitions in InAs quantum dots at telecommunication-wavelengths (1300-1500 nm)

Experimental and theoretical study of polarization-dependent optical transitions in InAs quantum dots at telecommunication-wavelengths (1300-1500 nm)

Investigation of Localized Electric Field in the Type-II InAs/GaAsSb/GaAs Structure

Transient band‐bending in InP/InAs/InP core‐multishell nanowires

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