Electro-optic properties of GaInAsSb/GaAs quantum well for high-speed integrated optoelectronic devices

Abstract

The electro-optic properties of strained GaInAsSb/GaAs quantum wells (QWs) are investigated. A single QW p-i-n sample was grown by molecular beam epitaxy with antimony (Sb) pre-deposition technique. We numerically predict and experimentally verify a strong quantum confined Stark shift of 40 nm. We also predict a fast absorption recovery times crucial of high-speed optoelectronic devices mainly due to strong electron tunneling and thermionic emission. Predicted recovery times are corroborated by bias and temperature dependent time-resolved photoluminescence measurements indicating (<= 30 ps) recovery times. This makes GaInAsSb QW an attractive material particularly for electroabsorption modulators and saturable absorbers. (C) 2013 American Institute of Physics. (http://dx.doi.org/10.1063/1.4775371

Time-Resolved Stark Spectroscopy in CdSe Nanoplatelets: Exciton Binding Energy, Polarizability, and Field-Dependent Radiative Rates

“…Robust excitons are desirable for many photonic applications (e.g., lasing) and are currently in the focus of interest as they occur in 2D semiconductor nanomaterials with strong confinement and high dielectric mismatch to the surrounding. , We expect these high exciton binding energies to allow high spectral modulation while preventing field ionization in field-controlled nanoemitters and nanostructure based modulators. This has great application potential in miniaturized and integrated photonics such as modulated emitters, switchable single photon sources, or ultra high bandwidth modulators. − We show that CdSe nanoplatelets exhibit high exciton binding energies of ≈170 meV in line with theoretical predictions. As those robust excitons are stable at room temperature and still efficiently polarizable, there is great application potential for field-dependent photoluminescence (PL) nanoemitters or modulators.…”

“…As those robust excitons are stable at room temperature and still efficiently polarizable, there is great application potential for field-dependent photoluminescence (PL) nanoemitters or modulators. While field-controlled electroabsorption based modulators have been studied intensively both in experiment and theory, ,,− field-dependent photoluminescence (PL) nanoemitters − have been mostly discussed on a qualitative or semiquantitative level. However, these studies investigated field effects on Wannier excitons with rather weak exciton binding energy in contrast to the nanoplatelets.…”

Electroabsorption by 0D, 1D, and 2D Nanocrystals: A Comparative Study of CdSe Colloidal Quantum Dots, Nanorods, and Nanoplatelets

“…The phenomenon of a change in the optical properties of semiconductor nanostructures in response to an electric field is employed in many photonics componentsincluding electro-optic modulators − and switches , and self-electro-optic-effect devices. , The most widely employed electro-optic components are those based on the semiconductor quantum wells (QWs) that are fabricated using the chemical vapor deposition (CVD) or molecular beam epitaxy (MBE) technique. , When a static electric field is applied to a QW, it results in the quantum-confined Stark effect (QCSE) and the quantum-confined Franz–Keldysh effect (QCFKE) . The former manifests itself in spectral shifts and broadening of the exciton absorption bands, as well as in changes in the intensities of the absorption maxima, whereas the latter leads to modulation of the absorption spectra and decrease of the interband transition energies.…”

“…NPLs are ultrathin and flat nanocrystals (typically made of CdSe, CdS, or CdTe) with lateral dimensions from a few to several tens of nanometers and thicknesses of several monolayers. − The strong anisotropic quantum confinement in the NPLs leads to extremely sharp peaks in the absorption and photoluminescence spectra of the NPLs at the room temperature. Since the lateral dimensions of NPLs are much larger than their thickness, the NPLs are the colloidal analogue of ultrathin semiconductor QWs prepared using the MBE. , This analogy suggests that colloidal NPLs could feature a strong electro-optic response desirable in optoelectronic applications. ,,,, …”

Carrier localization and in-situ annealing effect on quaternary Ga1−xInxAsySb1−y/GaAs quantum wells grown by Sb pre-deposition

“…At this point, we must emphasize that the 100 meV peak shift of the p-i-n sample comprises a mixture of two counterbalancing parts; first one (large blueshift) induced by in-situ annealing; and second one (minimal redshift) induced by embedding the QW into p-i-n junction leading to the quantum-confined Stark effect. In our previous report, 21 we studied an effect of applied electric field across the p-i-n sample and under the built-in electric field of 54 kV/cm the observed (almost negligible) redshift was about 2.2 meV (2.4 nm).…”