An array of SiGe nanodisks with Ge quantum dots on bulk Si substrates demonstrating a unique light–matter interaction associated with dual coupling

Wang, Shuguang; Chen, Peizong; Zhang, Lijian; Peng, Kun; Zhong, Zhenyang

doi:10.1039/c9nr00798a

Cited by 18 publications

(22 citation statements)

References 40 publications

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“…There is considerable interest in nanostructured materials from the group IV Si-Ge system for photonics applications [1][2][3][4][5][6][7][8][9][10]. However, the most important inconvenience of this system is the low light absorption-emission efficiency of bulk Si-Ge with an indirect band gap that counts against the long-held goal of integrated group IV photonics.…”

Section: Introductionmentioning

confidence: 99%

Nanocrystallized Ge-Rich SiGe-HfO2 Highly Photosensitive in Short-Wave Infrared

et al. 2021

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Group IV nanocrystals (NCs), in particular from the Si–Ge system, are of high interest for Si photonics applications. Ge-rich SiGe NCs embedded in nanocrystallized HfO2 were obtained by magnetron sputtering deposition followed by rapid thermal annealing at 600 °C for nanostructuring. The complex characterization of morphology and crystalline structure by X-ray diffraction, μ-Raman spectroscopy, and cross-section transmission electron microscopy evidenced the formation of Ge-rich SiGe NCs (3–7 nm diameter) in a matrix of nanocrystallized HfO2. For avoiding the fast diffusion of Ge, the layer containing SiGe NCs was cladded by very thin top and bottom pure HfO2 layers. Nanocrystallized HfO2 with tetragonal/orthorhombic structure was revealed beside the monoclinic phase in both buffer HfO2 and SiGe NCs–HfO2 layers. In the top part, the film is mainly crystallized in the monoclinic phase. High efficiency of the photocurrent was obtained in a broad spectral range of curves of 600–2000 nm at low temperatures. The high-quality SiGe NC/HfO2 matrix interface together with the strain induced in SiGe NCs by nanocrystallization of both HfO2 matrix and SiGe nanoparticles explain the unexpectedly extended photoelectric sensitivity in short-wave infrared up to about 2000 nm that is more than the sensitivity limit for Ge, in spite of the increase of bandgap by well-known quantum confinement effect in SiGe NCs.

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Section: Introductionmentioning

confidence: 99%

Nanocrystallized Ge-Rich SiGe-HfO2 Highly Photosensitive in Short-Wave Infrared

et al. 2021

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“…There is a considerable interest in nanostructured group IV semiconductor materials based on the Si–Ge–Sn system for optoelectronics, photovoltaics, and nanophotonics. − In nanocrystals (NCs) or quantum dots (QDs), the quantum confinement enhances the no-phonon optical transitions with respect to phonon-assisted ones in indirect band gap bulk material and it can be employed together with composition and strain engineering for tuning the optical and electronic properties in a broad range …”

Section: Introductionmentioning

confidence: 99%

Influence of SiGe Nanocrystallization on Short-Wave Infrared Sensitivity of SiGe–TiO₂ Films and Multilayers

et al. 2020

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Continuous development of Si photonics requires ecological and cost-effective materials. In this work, SiGe nanocrystals (NCs) embedded in TiO2 are investigated as a photosensitive material for visible (VIS) to short-wave infrared (SWIR) broad-range detection. The TiO2 matrix has the advantage of a lower band gap than SiO2, facilitating transport of photogenerated carriers in NCs. The advantage of SiGe NCs over Ge NCs is emphasized by elucidating the mechanisms involved in rapid thermal annealing (RTA)-induced nanocrystallization. An efficiently increased NC stabilization is achieved by avoiding the detrimental fast Ge diffusion. For this, the structure, morphology, and composition were carefully characterized by high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and Raman spectroscopy. Two types of structures were investigated, a film of SiGe–TiO2 alloy and a multilayer of a stack of six SiGe/TiO2 pairs. The layers have been deposited on Si wafers using magnetron sputtering of Si, Ge, and TiO2 followed by RTA in an inert atmosphere. The stabilization of SiGe NCs is achieved by the formation during RTA of protective SiO2 thin layers through Si oxidation at the SiGe NC surface, acting as a barrier for Ge diffusion. Thus, embedded Ge-rich SiGe NCs are obtained, resulting in the SWIR extension of the spectral photocurrent up to 1700 nm for films and 1600 nm for multilayers. This study has shown that in multilayers, the local anisotropy of crystallization is compensated by the stress field developed in the SiGe lattice, highly visible in the bottom part. Also, SiGe crystallizes faster than TiO2 in the rutile phase, and therefore, TiO2 remains mainly amorphous.

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“…38 It is the ideal cavity mode applied in enhancing the emission of QDs due to unique light con nement within the nanodisk. 39 The electric eld for peak P3 in Fig. 4e indicates a vertically oriented magnetic dipole mode.…”

Section: Optical Properties Of H-ge Nanostructuresmentioning

confidence: 94%

“…Whereas, the emissions of H-Ge can be remarkably enhanced and characterized by coupling into the cavity modes supported in SiGe nanodisk array. 39 Given the full compatibility with the Si integration technology and the suitable wavelength around 1550 nm for communication, H-Ge nanostructures embedded in the metasurface can be a promising candidate for the innovative light source in the Si-based MOEICs. In addition, it has been found that the group III dopant can be more easily introduced in the H-Ge due to the local C 3v symmetry, 46 in comparison with the C-Ge.…”

Section: Optical Properties Of H-ge Nanostructuresmentioning

confidence: 99%

Unique hexagonal-Ge nanostructures with direct-bandgap emissions in Si-based light-emitting metasurface

Jia

Wang

Zhang

et al. 2022

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Si-based emitters have been of great interest due to their potential as the ideal light source for monolithic optical-electronic integrated circuits (MOEICs) on Si substrates. However, the general Si-based material is a diamond structure of cubic lattice with an indirect-bandgap, which cannot emit light efficiently. Here, unique hexagonal-Ge (H-Ge) nanostructures within light-emitting metasurface consisted of cubic-SiGe nanodisk array are reported. The H-Ge nanostructure is naturally formed within the cubic-Ge epitaxially grown on Si (001) substrates due to the strain-induced crystal phase transition assisted with far-from equilibrium growth conditions. The direct-bandgap features of H-Ge nanostructures are observed and discussed, including a rather strong and linearly power-dependent PL peak around 1560 nm at room temperature, temperature-insensitive PL spectrum above 160 K. Given the direct-bandgap nature and the compatibly with the sophisticated Si technology, the H-Ge nanostructure within a light-emitting metasurface has great potentials for innovative light sources, particularly in Si-based MOEICs.

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An array of SiGe nanodisks with Ge quantum dots on bulk Si substrates demonstrating a unique light–matter interaction associated with dual coupling

Abstract: An array of SiGe nanodisks with Ge quantum dots is realized directly on bulk Si substrates, demonstrating a unique light–matter interaction.

Cited by 18 publications

References 40 publications

Nanocrystallized Ge-Rich SiGe-HfO2 Highly Photosensitive in Short-Wave Infrared

Nanocrystallized Ge-Rich SiGe-HfO2 Highly Photosensitive in Short-Wave Infrared

Influence of SiGe Nanocrystallization on Short-Wave Infrared Sensitivity of SiGe–TiO₂ Films and Multilayers

Unique hexagonal-Ge nanostructures with direct-bandgap emissions in Si-based light-emitting metasurface

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An array of SiGe nanodisks with Ge quantum dots on bulk Si substrates demonstrating a unique light–matter interaction associated with dual coupling

Abstract: An array of SiGe nanodisks with Ge quantum dots is realized directly on bulk Si substrates, demonstrating a unique light–matter interaction.

Cited by 18 publications

References 40 publications

Nanocrystallized Ge-Rich SiGe-HfO2 Highly Photosensitive in Short-Wave Infrared

Nanocrystallized Ge-Rich SiGe-HfO2 Highly Photosensitive in Short-Wave Infrared

Influence of SiGe Nanocrystallization on Short-Wave Infrared Sensitivity of SiGe–TiO2 Films and Multilayers

Unique hexagonal-Ge nanostructures with direct-bandgap emissions in Si-based light-emitting metasurface

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Influence of SiGe Nanocrystallization on Short-Wave Infrared Sensitivity of SiGe–TiO₂ Films and Multilayers