Enhancement in the gain of quantum dot laser by increasing overlap integral between electron and hole wave-functions

Jo, Byounggu; Yang, Youngsin; Kim, Jaesu; Ko, Myoungkuk; Lee, Kwang Jae; Lee, Cheul-Ro; Choi, Byoung Seok; Oh, Dae Kon; Leem, Jae‐Young; Kim, Jong Su

doi:10.1016/j.tsf.2009.01.110

Cited by 4 publications

(3 citation statements)

References 23 publications

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“…The achieved threshold current density, Qdot density and lasing wavelength were 2.8 kA/cm [42]. Furthermore, the AGQD laser performance was shown to be better than CQD laser performance which was attributed to the increase in the overlap integral between the electron and hole wave-functions due to two times increase in the aspect ratio (height/width) of the AGQD compared to CQD [113]. More details of the AGQD and CQD Qdot growth was discussed in section 2.1.2. response of ridge waveguide tunnel injection quantum dot laser.…”

Section: Lasers On (100) Inp Substratementioning

confidence: 96%

Self-assembled InAs/InP quantum dots and quantum dashes: Material structures and devices

Khan

Ooi

2014

Progress in Quantum Electronics

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The advances in lasers, electronic and photonic integrated circuits (EPIC), optical interconnects as well as the modulation techniques allow the present day society to embrace the convenience of broadband, high speed internet and mobile network connectivity. However, the steep increase in energy demand and bandwidth requirement calls for further innovation in ultra-compact EPIC technologies. In the optical domain, innovation in the laser technologies beyond the current quantum well (Qwell) based laser technologies are already taking place and presenting very promising results. Homogeneously grown quantum dot (Qdot) lasers, can serve in the future energy saving information and communication technologies (ICT) as the work-horse for transmitting information through optical fiber. The encouraging results in the zero-dimensional (0D) structures emitting at 980 nm, in the form of vertical cavity surface emitting laser (VCSEL), are already operational at low threshold current density and capable of 40 Gbps error-free transmission at 108 fJ/bit. Eventual achievements for lasers operating in the O-, C-, L-, U-bands, and beyond will eventually lay the foundation for green ICT. On the hand, the inhomogeneously grown quasi 0D quantum dash (Qdash) lasers are brilliant solutions for potential broadband connectivity in server farms or access network. A single broadband Qdash laser operating in the stimulated emission mode can replace tens of discrete narrow-band lasers in dense wavelength division multiplexing (DWDM) transmission thereby further saving energy, cost and footprint. In this article, we review the progress of both Qdots and Qdash devices based on the InAs/InGaAlAs/InP and InAs/InGaAsP/InP material systems, from the angles of growth and device performance.2

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Section: Lasers On (100) Inp Substratementioning

confidence: 96%

Self-assembled InAs/InP quantum dots and quantum dashes: Material structures and devices

Khan

Ooi

2014

Progress in Quantum Electronics

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“…An appropriate synthesis allows for the fabrication of QDs with different diameters and high-fluorescence quantum yield. Therefore, there are many potential application fields for QDs like LEDs, [1][2][3][4][5] lasers, [6][7][8][9] photovoltaic devices, [10][11][12][13] or fluorescence markers in biological systems. [14,15] Absorption of a photon with an appropriate wavelength leads to the generation of an electron-hole pair (exciton), which is delocalized throughout the QD.…”

Section: Introductionmentioning

confidence: 99%

Ultrafast Electron Transfer from Photoexcited CdSe Quantum Dots to Methylviologen

et al. 2011

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The ultrafast charge separation at the quantum dot (QD)/molecular acceptor interface was investigated in terms of acceptor concentration and the size of the QD. Time-resolved experiments revealed that the electron transfer (ET) from the photoexcited QD to the molecular acceptor methylviologen (MV(2+)) occurs on the fs time scale for large acceptor concentrations and that the ET rate is strongly reduced for low concentrations. The increase in the acceptor concentration is accompanied with a growth in the overlap of donor and acceptor wavefunctions, resulting in a faster reaction until the MV(2+) concentration reaches a saturation limit of 0.3-0.4 MV(2+) nm(-2). Moreover, we found significant QD size dependence of the ET reaction, which is explained by a change of the free energy (ΔG).

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“…The piezoelectric field induced by an external strain compensates the built-in electrostatic field, which makes the energy band of the InGaN layer flatter. As a consequence, the overlap of electron and hole wave functions is enhanced, decreasing the carrier lifetime and increasing the transition probability [43]. The single-chip modulation width can easily be up to 117 MHz by the piezo-phototronic effect, significantly higher than commercial LEDs.…”

Section: Dynamic (Time-resolution) Piezo-phototronic Effectmentioning

confidence: 99%

III-nitride piezotronic/piezo-phototronic materials and devices

Sha

Zhang

Tan

et al. 2019

J. Phys. D: Appl. Phys.

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Benefiting from the unique non-central symmetric crystal structure, groups II-VI and III-V wurtzite semiconductors, for example, ZnO, AlN, GaN, and InN, possess the piezoelectric property. Carrier behaviors, including generation, transport, separation, and recombination, can be effectively modulated/controlled by piezotronic and piezo-phototronic effects, that control the piezoelectric polarization charges generated at the interface via applying external stress on the polarization orientation of these semiconductors, and then form the piezopotential used as a 'gate' to tune and further improve the performance of semiconductor devices. Based on these advanced properties, a large number of piezotronic and piezo-phototronic devices and applications have been researched, like light emitting diodes, solar cells, sensors, human-machine interfaces, nanogenerators, and so on, and suggest the dramatic improvement of operating efficiency compared to that with no external strain. Moreover, piezotronic and piezo-phototronic effects provide a convenient and economical method to effectively relieve various issues of semiconductor devices, instead of the traditional ways, requiring complicated design, high costs, and a long period of time. This brief review mainly concentrates on the fundamental physical mechanism and correlative devices and applications on emerging piezotronic and piezo-phototronic effects, and wishes to provide scientific guidance on potential functional applications for the future.

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Enhancement in the gain of quantum dot laser by increasing overlap integral between electron and hole wave-functions

Cited by 4 publications

References 23 publications

Self-assembled InAs/InP quantum dots and quantum dashes: Material structures and devices

Self-assembled InAs/InP quantum dots and quantum dashes: Material structures and devices

Ultrafast Electron Transfer from Photoexcited CdSe Quantum Dots to Methylviologen

III-nitride piezotronic/piezo-phototronic materials and devices

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