Photoluminescence from In0.5Ga0.5As/GaP quantum dots coupled to photonic crystal cavities

We demonstrate room temperature visible wavelength photoluminescence from In0.5Ga0.5As quantum dots embedded in a GaP membrane. Time-resolved above band photoluminescence measurements of quantum dot emission show a biexpontential decay with lifetimes of ~200 ps. We fabricate photonic crystal cavities which provide enhanced outcoupling of quantum dot emission, allowing the observation of narrow lines indicative of single quantum dot emission. This materials system is compatible with monolithic integration on Si, and is promising for high efficiency detection of single quantum dot emission as well as optoelectronic devices emitting at visible wavelengths

Review Article: Molecular Beam Epitaxy of Lattice-Matched InAlAs and InGaAs Layers on InP (111)A, (111)B, and (110)

For more than 50 years, research into III–V compound semiconductors has focused almost exclusively on materials grown on (001)-oriented substrates. In part, this is due to the relative ease with which III–Vs can be grown on (001) surfaces. However, in recent years, a number of key technologies have emerged that could be realized, or vastly improved, by the ability to also grow high-quality III–Vs on (111)- or (110)-oriented substrates These applications include: next-generation field-effect transistors, novel quantum dots, entangled photon emitters, spintronics, topological insulators, and transition metal dichalcogenides. The first purpose of this paper is to present a comprehensive review of the literature concerning growth by molecular beam epitaxy (MBE) of III–Vs on (111) and (110) substrates. The second is to describe our recent experimental findings on the growth, morphology, electrical, and optical properties of layers grown on non-(001) InP wafers. Taking InP(111)A, InP(111)B, and InP(110) substrates in turn, the authors systematically discuss growth of both In0.52Al0.48As and In0.53Ga0.47As on these surfaces. For each material system, the authors identify the main challenges for growth, and the key growth parameter–property relationships, trends, and interdependencies. The authors conclude with a section summarizing the MBE conditions needed to optimize the structural, optical and electrical properties of GaAs, InAlAs and InGaAs grown with (111) and (110) orientations. In most cases, the MBE growth parameters the authors recommend will enable the reader to grow high-quality material on these increasingly important non-(001) surfaces, paving the way for exciting technological advances

Bulk AlInAs on InP(111) as a novel material system for pure single photon emission

In this letter, we report on quantum light emission from bulk AlInAs grown on InP(111) substrates. We observe indium rich clusters in the bulk Al0:48In0:52As (AlInAs), resulting in quantum dot-like energetic traps for charge carriers, which are confirmed via cross-sectional scanning tunnelling microscopy (XSTM) measurements and 6-band k•p simulations. We observe quantum dot (QD)-like emission signals, which appear as sharp lines in our photoluminescence spectra at near infrared wavelengths around 860 nm, and with linewidths as narrow as 50 meV. We demonstrate the capability of this new material system to act as an emitter of pure single photons as we extract g(2)-values as low as g(2)/cw (0) = 0:05+0:17/-0:05 for continuous wave (cw) excitation and g (2) pulsed, corr. = 0:24 ± 0:02 for pulsed excitation.PostprintPeer reviewe

10-Fold-Stack Multilayer-Grown Nanomembrane GaAs Solar Cells

Multilayer-grown nanomembrane GaAs represents an enabling materials platform for cost-efficient III–V photovoltaics. Herein we present for the first time 10-fold-stack ultrathin (emitter + base: 300 nm) GaAs solar cells. Photovoltaic performance of 10-fold-stack GaAs solar cells exhibited promising uniformity, with only slight efficiency degradation, where comparatively poor short-wavelength response was mainly responsible for the slightly reduced performance in early grown materials. Secondary ion mass spectrometry revealed the concentration of p-type dopant has been changed due to the out-diffusion of beryllium, while the extent of diffusion increasingly diminished in early grown stacks because of the reduced concentration gradient as well as the decrease of beryllium diffusivity at longer annealing times. It is therefore concluded that the performance degradation in 10-fold-stack GaAs solar cells does not develop continuously throughout the growth, but instead becomes spontaneously saturated at longer growth times, providing promising outlook for the practical application of multilayer epitaxy toward cost-competitive GaAs solar cells

Bulk AlInAs on InP(111) as a novel material system for pure single photon emission

In this letter, we report on quantum light emission from bulk AlInAs grown on InP(111) substrates. We observe indium rich clusters in the bulk Al0.48In0.52As (AlInAs), resulting in quantum dot-like energetic traps for charge carriers, which are confirmed via cross-sectional scanning tunnelling microscopy (XSTM) measurements and 6-band k·p simulations. We observe quantum dot (QD)-like emission signals, which appear as sharp lines in our photoluminescence spectra at near infrared wavelengths around 860 nm, and with linewidths as narrow as 50 μeV. We demonstrate the capability of this new material system to act as an emitter of pure single photons as we extract g(2)-values as low as gcw(2)(0) = 0.05-0.05+0.17 for continuous wave (cw) excitation and gpulsed, corr.(2) = 0.24 ± 0.02 for pulsed excitation

Bulk AlInAs on InP(111) as a novel material system for pure single photon emission

\u3cp\u3eIn this letter, we report on quantum light emission from bulk AlInAs grown on InP(111) substrates. We observe indium rich clusters in the bulk Al\u3csub\u3e0.48\u3c/sub\u3eIn\u3csub\u3e0.52\u3c/sub\u3eAs (AlInAs), resulting in quantum dot-like energetic traps for charge carriers, which are confirmed via cross-sectional scanning tunnelling microscopy (XSTM) measurements and 6-band k·p simulations. We observe quantum dot (QD)-like emission signals, which appear as sharp lines in our photoluminescence spectra at near infrared wavelengths around 860 nm, and with linewidths as narrow as 50 μeV. We demonstrate the capability of this new material system to act as an emitter of pure single photons as we extract g\u3csup\u3e(2)\u3c/sup\u3e-values as low as g\u3csub\u3ecw\u3c/sub\u3e\u3csup\u3e(2)\u3c/sup\u3e(0) = 0.05\u3csub\u3e-0.05\u3c/sub\u3e\u3csup\u3e+0.17\u3c/sup\u3e for continuous wave (cw) excitation and g\u3csub\u3epulsed, corr.\u3c/sub\u3e\u3csup\u3e(2)\u3c/sup\u3e = 0.24 ± 0.02 for pulsed excitation.\u3c/p\u3