| 1181. |
- Wang, L, et al.
(författare)
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Influence of Bi on morphology and optical properties of InAs QDs
- 2017
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Ingår i: Optical Materials Express. - 2159-3930. ; 7:12, s. 4249-4257
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Tidskriftsartikel (refereegranskat)abstract
- We study the tsurface morphology and photoluminescence (PL) property of InAs quantum dots (QDs) on GaAs using bismuth (Bi) in the layer prior to or after the growth of QDs. Incorporating Bi in the layer prior to the QD deposition delays the onset of InAs QD formation resulting in a decrease in QD height and density. As a surfactant, adding Bi in the GaAs capping layer at a high growth temperature reduces the In surface diffusion length leading to uniform and well preserved InAs QDs in terms of height and density. The incorporation of 3% Bi at a low growth temperature, which forms a GaAsBi capping layer, can effectively lower the PL transition energy up to 163 meV and reduce the PL linewidth, leading to an emission wavelength of 1.365 ?m at 77 K.
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| 1182. |
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| 1183. |
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| 1184. |
- Wang, P., et al.
(författare)
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Detailed Study of the Influence of InGaAs Matrix on the Strain Reduction in the InAs Dot-In-Well Structure
- 2016
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Ingår i: Nanoscale Research Letters. - : Springer Science and Business Media LLC. - 1556-276X .- 1931-7573. ; 11:1, s. Article Number: 119-6
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Tidskriftsartikel (refereegranskat)abstract
- InAs/InGaAs dot-in-well (DWELL) structures have been investigated with the systematically varied InGaAs thickness. Both the strained buffer layer (SBL) below the dot layer and the strain-reducing layer (SRL) above the dot layer were found to be responsible for the redshift in photoluminescence (PL) emission of the InAs/InGaAs DWELL structure. A linear followed by a saturation behavior of the emission redshift was observed as a function of the SBL and SRL thickness, respectively. The PL intensity is greatly enhanced by applying both of the SRL and SBL. Finite element analysis simulation and transmission electron microscopy (TEM) measurement were carried out to analyze the strain distribution in the InAs QD and the InGaAs SBL. The results clearly indicate the strain reduction in the QD induced by the SBL, which are likely the main cause for the emission redshift.
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| 1185. |
- Wang, P., et al.
(författare)
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Heteroepitaxy growth of GaAsBi on Ge(100) substrate by gas source molecular beam epitaxy
- 2016
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Ingår i: Applied Physics Express. - : IOP Publishing. - 1882-0786 .- 1882-0778. ; 9:4
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the growth of GaAsBi single-crystal film on Ge substrate by gas source molecular beam epitaxy. A high-quality GaAsBi epilayer has been obtained. It has been found that the surfactant effect of Bi suppresses the interdiffusion of Ge at the GaAsBi/Ge interface and reduces the misfit dislocation density. The Bi atoms occupy the As sites, as indicated by the appearance of GaBi-like TO(G) and LO(G) phonon modes in Raman spectra. In addition, the redshift of the GaAs-like LO(G) phonon frequency has been observed in the Raman spectra, owing to the Bi-induced biaxial strain and the alloying effect as well.
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| 1186. |
- Wang, P., et al.
(författare)
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Influence of GaAsBi Matrix on Optical and Structural Properties of InAs Quantum Dots
- 2016
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Ingår i: Nanoscale Research Letters. - : Springer Science and Business Media LLC. - 1556-276X .- 1931-7573. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- InAs/GaAsBi dot-in-well structures were fabricated using gas-source molecular beam epitaxy and investigated for its optical and structural properties. GaAsBi-strained buffer layer and strain reduction layer are both effective to extend the photoluminescence (PL) emission wavelength of InAs quantum dot (QD). In addition, a remarkable PL intensity enhancement is also obtained compared with low-temperature-grown GaAs-capped InAs QD sample. The GaAsBi matrix also preserves the shape of InAs QDs and leads to increase the activation energy for nonradiative recombination process at low temperature. Lower density and larger size of InAs QDs are obtained on the GaAsBi surface compared with the QDs grown on GaAs surface.
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| 1187. |
- Wang, P., et al.
(författare)
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Investigation to the deep center related properties of low temperature grown InPBi with Hall and photoluminescence
- 2015
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Ingår i: AIP Advances. - : AIP Publishing. - 2158-3226 .- 2158-3226. ; 5:12, s. Art. no. 127104-
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Tidskriftsartikel (refereegranskat)abstract
- InP1-xBix epilayers with bismuth (Bi) concentration x= 1.0% were grown on InP by gas source molecular beam epitaxy (GS-MBE) at low temperature (LT). Bi incorporation decreased the intrinsic free electron concentration of low temperature grown InP indicated by hall analysis. It is concluded that deep level center was introduced by Bi. Influence of Si doping on the InP1-xBix films Photoluminescence (PL) was investigated. N-type doping in the InP1-xBix epilayers was found to be effective at PL enhancement. Blue shift of InPBi PL emission wavelength was observed as the Si doping concentration increasing. Two independent peaks were fitted and their temperature dependence behavior was observed to be distinct obviously. Two individual radiative recombination processes were expected to be involved.
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| 1188. |
- Wang, Shu Min, 1963, et al.
(författare)
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Novel Dilute InPBi for IR Emitters
- 2014
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Ingår i: International Conference on Transparent Optical Networks. - 2162-7339. - 9781479956005 ; , s. Article number 6876587-
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Konferensbidrag (refereegranskat)abstract
- InPBi crystalline thin films with a bismuth concentration up to 4.8% have been successfully grown using molecular beam epitaxy for the first time. This novel material reveals strong and broad photoluminescence in the wavelength range of 1-2.5 μm at room temperature, although the absorption measurements point out a near band-gap absorption character. Various structural and optical characterization techniques are used to assess material quality and to understand the physical origins of the unexpected light emission. The InPBi is almost lattice matched to InP, making such a material very promising for InP based optoelectronics devices. The emitted light covers the telecom wavelength regime as well as other important wavelengths for gas sensing. The very broad emission spectrum of more than 600 nm promises for making super-luminescence IR diodes that have potentials to significantly enhance the spatial resolution in optical coherence tomography (OCT).
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| 1189. |
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| 1190. |
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