Recent advancements in quantum key distribution (QKD) protocols opened the chance to exploit nonl... more Recent advancements in quantum key distribution (QKD) protocols opened the chance to exploit nonlaser sources for their implementation. A possible solution might consist in erbium-doped light emitting diodes (LEDs), which are able to produce photons in the third communication window, with a wavelength around 1550 nm. Here, we present silicon LEDs based on the electroluminescence of Er:O complexes in Si. Such sources are fabricated with a fully-compatible CMOS process on a 220 nm-thick silicon-on-insulator (SOI) wafer, the common standard in silicon photonics. The implantation depth is tuned to match the center of the silicon layer. The erbium and oxygen co-doping ratio is tuned to optimize the electroluminescence signal. We fabricate a batch of Er:O diodes with surface areas ranging from 1 µm × 1 µm to 50 µm × 50 µm emitting 1550 nm photons at room temperature. We demonstrate emission rates around 5 × 106 photons/s for a 1 µm × 1 µm device at room temperature using superconducting n...
We report on the dewetting process, in a high vacuum environment, of amorphous Ge thin films on S... more We report on the dewetting process, in a high vacuum environment, of amorphous Ge thin films on SiO2/Si (001). A detailed insight of the dewetting is obtained by in situ reflection high-energy electron diffraction and ex situ scanning electron microscopy. These characterizations show that the amorphous Ge films dewet into Ge crystalline nano-islands with dynamics dominated by crystallization of the amorphous material into crystalline nano-seeds and material transport at Ge islands. Surface energy minimization determines the dewetting process of crystalline Ge and controls the final stages of the process. At very high temperatures, coarsening of the island size distribution is observed.
The finite spin lifetime in solids is often considered a major hindrance for the development of s... more The finite spin lifetime in solids is often considered a major hindrance for the development of spintronic devices, which typically require cryogenic temperatures to mitigate this phenomenon. In this work, we show that this feature can instead be exploited to realize a scheme where spin transport is modulated at room temperature by a modest electric field. A field directed antiparallel (parallel) to the spin-diffusion velocity can, in fact, largely increase (decrease) the spin-transport length compared with the zero field case. We find that applying an electric field E = 24 V/cm along a 40 μm-long path in germanium results in about one order of magnitude modulation of the spin-polarized electrons entering into the detector. This work demonstrates that electric fields can be exploited for guiding spins over macroscopic distances and for realizing fast room temperature modulation of spin accumulation.
Vertical optical confinement is a critical requirement for a wide range of III-V photonic devices... more Vertical optical confinement is a critical requirement for a wide range of III-V photonic devices where Al2O3 material is the typical oxide used due to its low refractive index. This oxide layer can be formed from the oxidation of AlAs in an epitaxial GaAs/AlAs/GaAs or AlGaAs/AlAs/GaAs stack, with the advantage that the top layer remains single-crystalline. The thick film oxidation of AlAs is required for photonic applications. In this article, we report the oxidation processes developed to fully convert AlAs to AlOx films by analyzing both thin (100 nm) and thick (500 nm) AlAs films on GaAs (001) and 2° miscut GaAs (111)A substrate. Systematic microscopic characterization is performed to demonstrate the absence of any delamination at the oxide interfaces and the evolution of the diffusive oxidation process microscopically characterized is compared with an optical (µ-Raman) characterization. We demonstrate the selectivity of the AlAs oxidation process with respect to the active Al0....
Metasurfaces are versatile tools for manipulating light; however, they have received little atten... more Metasurfaces are versatile tools for manipulating light; however, they have received little attention as devices for the efficient control of nonlinearly diffracted light. Here, we demonstrate nonlinear wavefront control through third-harmonic generation (THG) beaming into diffraction orders with efficiency tuned by excitation of hybrid Mie−quasi-bound states in the continuum (BIC) modes in a silicon metasurface. Simultaneous excitation of the high-Q collective Mie-type modes and quasi-BIC modes leads to their hybridization and results in a local electric field redistribution. We probe the hybrid mode by measuring far-field patterns of THG and observe the strong switching between (0,−1) and (−1,0) THG diffraction orders from 1:6 for off-resonant excitation to 129:1 for the hybrid mode excitation, showing tremendous contrast in controlling the nonlinear diffraction patterns. Our results pave the way to the realization of metasurfaces for novel light sources, telecommunications, and quantum photonics.
2021 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), 2021
Hot electron-based devices are quite promissing for ultrafast photodetection and to set off enhan... more Hot electron-based devices are quite promissing for ultrafast photodetection and to set off enhanced physicochemical reactions [1] . Controlling their generation at the nanoscale within plasmonic devices is a key for the future development of hybrid hot-electrons technologies. Indeed, Surface Plasmon-Polaritons (SPPs) can be exploited to confine light and enhance the number of excited hot carriers [2] . We aim at studying the excitation and dynamics of hot electrons, enhanced by plasmonics, with two different approaches.
We report on a systematic analysis of phosphorus diffusion in silicon on insulator thin film via ... more We report on a systematic analysis of phosphorus diffusion in silicon on insulator thin film via spin-on-dopant process (SOD). This method is used to provide an impurity source for semiconductor junction fabrication. The dopant is first spread into the substrate via SOD and then diffused by a rapid thermal annealing process. The dopant concentration and electron mobility were characterized at room and low temperature by four-probe and Hall bar electrical measurements. Time-of-flight-secondary ion mass spectroscopy was performed to estimate the diffusion profile of phosphorus for different annealing treatments. We find that a high phosphorous concentration (greater than 1020 atoms cm−3) with a limited diffusion of other chemical species and allowing to tune the electrical properties via annealing at high temperature for short time. The ease of implementation of the process, the low cost of the technique, the possibility to dope selectively and the uniform doping manufactured with sta...
We demonstrate the feasibility of growing GaAs nanomembranes on a plastically-relaxed Ge layer de... more We demonstrate the feasibility of growing GaAs nanomembranes on a plastically-relaxed Ge layer deposited on Si (111) by exploiting selective area epitaxy in MBE. Our results are compared to the case of the GaAs homoepitaxy to highlight the criticalities arising by switching to heteroepitaxy. We found that the nanomembranes evolution strongly depends on the chosen growth parameters as well as mask pattern. The selectivity of III-V material with respect to the SiO2 mask can be obtained when the lifetime of Ga adatoms on SiO2 is reduced, so that the diffusion length of adsorbed Ga is high enough to drive the Ga adatoms towards the etched slits. The best condition for a heteroepitaxial selective area epitaxy is obtained using a growth rate equal to 0.3 ML/s of GaAs, with a As BEP pressure of about 2.5 × 10−6 torr and a temperature of 600 °C.
No further publication processing will occur until we receive your response to this proof. Attach... more No further publication processing will occur until we receive your response to this proof. Attached is a PDF proof of your forthcoming article in Physical Review Materials. Your article has 8 pages and the Accession Code is ME10125. Please note that as part of the production process, APS converts all articles, regardless of their original source, into standardized XML that in turn is used to create the PDF and online versions of the article as well as to populate third-party systems such as Portico, Crossref, and Web of Science. We share our authors' high expectations for the fidelity of the conversion into XML and for the accuracy and appearance of the final, formatted PDF. This process works exceptionally well for the vast majority of articles; however, please check carefully all key elements of your PDF proof, particularly any equations or tables.
We demonstrate the use of plasmonic effects to boost the near-infrared sensitivity of metal-semic... more We demonstrate the use of plasmonic effects to boost the near-infrared sensitivity of metal-semiconductor-metal detectors. Plasmon-enhanced photodetection is achieved by properly optimizing Au interdigitated electrodes, micro-fabricated on Ge, a semiconductor that features a strong near IR absorption. Finite-difference time-domain simulations, photocurrent experiments and Fourier-transform IR spectroscopy are performed to validate how a relatively simple tuning of the contact geometry allows for an enhancement of the response of the device adapting it to the specific detection needs. A 2-fold gain factor in the Ge absorption characteristics is experimentally demonstrated at 1.4 µm, highlighting the potential of this approach for optoelectronic and sensing applications.
Buried-channel semiconductor heterostructures are an archetype material platform to fabricate gat... more Buried-channel semiconductor heterostructures are an archetype material platform to fabricate gated semiconductor quantum devices. Sharp confinement potential is obtained by positioning the channel near the surface, however nearby surface states degrade the electrical properties of the starting material. In this paper we demonstrate a two-dimensional hole gas of high mobility (5 × 10 5 cm 2 /Vs) in a very shallow strained germanium channel, which is located only 22 nm below the surface. This high mobility leads to mean free paths ≈ 6µm, setting new benchmarks for holes in shallow FET devices. Carriers are confined in an undoped Ge/SiGe heterostructure with reduced background contamination, sharp interfaces, and high uniformity. The top-gate of a dopant-less field effect transistor controls the carrier density in the channel. The high mobility, along with a percolation density of 1.2 × 10 11 cm −2 , light effective mass (0.09 me), and high g-factor (up to 7) highlight the potential of undoped Ge/SiGe as a low-disorder material platform for hybrid quantum technologies. Recently, Ge/SiGe heterostructures have emerged as a
A novel scanning probe tip made of heavily doped semiconductor is fabricated and used instead of ... more A novel scanning probe tip made of heavily doped semiconductor is fabricated and used instead of standard gold-coated tips in infrared scattering-type near-field microscopy. Mid-infrared near-field microscopy experiments were conducted on ZnO nanowires with a lateral resolution better than 100 nm, using tips made of heavily electrondoped germanium with plasma frequency in the mid-infrared (plasma wavelength of 9.5 μm). Nanowires embedded in a dielectric matrix were imaged at two wavelengths, 11.3 μm and 8.0 μm, above and below the plasma wavelength of the tips. An opposite sign of the imaging contrasts between the nanowire and the dielectric matrix was observed at the two infrared wavelengths, indicating a clear role of the free electron plasma in the heavily doped germanium tip in building the imaging contrast. Electromagnetic simulations with a multi-spherical dipole model accounting for the finite size of the tip are well consistent with the experiments. By comparison of the simulated and measured imaging contrasts, an estimate for the local free carrier density in the investigated ZnO nanowires in the low 10 19 cm-3 range is retrieved. The results are benchmarked against the scattering intensity and phase maps obtained on the same sample with a goldcoated probe tip in pseudo-heterodyne detection mode.
Dewetting is a ubiquitous phenomenon in nature; many different thin films of organic and inorgani... more Dewetting is a ubiquitous phenomenon in nature; many different thin films of organic and inorganic substances (such as liquids, polymers, metals, and semiconductors) share this shape instability driven by surface tension and mass transport. Via templated solid-state dewetting, we frame complex nanoarchitectures of monocrystalline silicon on insulator with unprecedented precision and reproducibility over large scales. Phase-field simulations reveal the dominant role of surface diffusion as a driving force for dewetting and provide a predictive tool to further engineer this hybrid top-down/bottom-up self-assembly method. Our results demonstrate that patches of thin monocrystalline films of metals and semiconductors share the same dewetting dynamics. We also prove the potential of our method by fabricating nanotransfer molding of metal oxide xerogels on silicon and glass substrates. This method allows the novel possibility of transferring these Si-based patterns on different materials,...
We discuss a new type of nanoscale photon source constituted by a micro-pyramid made of epitaxial... more We discuss a new type of nanoscale photon source constituted by a micro-pyramid made of epitaxial semiconductor material (Ge) attached to a silicon cantilever optimized for Atomic Force Microscopy and shaped by means of low-current Focused Ion Beam (FIB) milling.. The optical characterization of these tips demonstrates sizeable photoluminescence emission at the direct energy gap of Ge (1550 nm). We have checked by independent measurements on the nano-patterned epitaxial material prior to the tip shaping process that the photoluminescence yield is not significantly affected by FIB milling, indicating that the optical properties of the material in this wavelength range are preserved. We envisage an application of this tool as a scanning probe in apertureless scanning near-field optical microscopy. High-resolution optical imaging has become a fundamental tool in nanoscience and nanotechnology and is playing a key role in physical sciences, biology, medicine and telecommunications. The majority of far-field optical microscopy techniques are extensively used for imaging biological samples, but they hardly overcome light diffraction, setting a limit to the lateral resolution that is slightly below the optical wavelength (0.4 to 1.5 m
In this work we address optical orientation, a process consisting in the excitation of spin polar... more In this work we address optical orientation, a process consisting in the excitation of spin polarized electrons across the gap of a semiconductor. We show that the combination of optical orientation with spin-dependent scattering leading to the inverse spin-Hall effect, i.e., to the conversion of a spin current into an electrical signal, represents a powerful tool to generate and detect spin currents in solids. We consider a few examples where these two phenomena together allow addressing the spin-dependent transport properties across homogeneous samples or metal/semiconductor Schottky junctions.
Recent advancements in quantum key distribution (QKD) protocols opened the chance to exploit nonl... more Recent advancements in quantum key distribution (QKD) protocols opened the chance to exploit nonlaser sources for their implementation. A possible solution might consist in erbium-doped light emitting diodes (LEDs), which are able to produce photons in the third communication window, with a wavelength around 1550 nm. Here, we present silicon LEDs based on the electroluminescence of Er:O complexes in Si. Such sources are fabricated with a fully-compatible CMOS process on a 220 nm-thick silicon-on-insulator (SOI) wafer, the common standard in silicon photonics. The implantation depth is tuned to match the center of the silicon layer. The erbium and oxygen co-doping ratio is tuned to optimize the electroluminescence signal. We fabricate a batch of Er:O diodes with surface areas ranging from 1 µm × 1 µm to 50 µm × 50 µm emitting 1550 nm photons at room temperature. We demonstrate emission rates around 5 × 106 photons/s for a 1 µm × 1 µm device at room temperature using superconducting n...
We report on the dewetting process, in a high vacuum environment, of amorphous Ge thin films on S... more We report on the dewetting process, in a high vacuum environment, of amorphous Ge thin films on SiO2/Si (001). A detailed insight of the dewetting is obtained by in situ reflection high-energy electron diffraction and ex situ scanning electron microscopy. These characterizations show that the amorphous Ge films dewet into Ge crystalline nano-islands with dynamics dominated by crystallization of the amorphous material into crystalline nano-seeds and material transport at Ge islands. Surface energy minimization determines the dewetting process of crystalline Ge and controls the final stages of the process. At very high temperatures, coarsening of the island size distribution is observed.
The finite spin lifetime in solids is often considered a major hindrance for the development of s... more The finite spin lifetime in solids is often considered a major hindrance for the development of spintronic devices, which typically require cryogenic temperatures to mitigate this phenomenon. In this work, we show that this feature can instead be exploited to realize a scheme where spin transport is modulated at room temperature by a modest electric field. A field directed antiparallel (parallel) to the spin-diffusion velocity can, in fact, largely increase (decrease) the spin-transport length compared with the zero field case. We find that applying an electric field E = 24 V/cm along a 40 μm-long path in germanium results in about one order of magnitude modulation of the spin-polarized electrons entering into the detector. This work demonstrates that electric fields can be exploited for guiding spins over macroscopic distances and for realizing fast room temperature modulation of spin accumulation.
Vertical optical confinement is a critical requirement for a wide range of III-V photonic devices... more Vertical optical confinement is a critical requirement for a wide range of III-V photonic devices where Al2O3 material is the typical oxide used due to its low refractive index. This oxide layer can be formed from the oxidation of AlAs in an epitaxial GaAs/AlAs/GaAs or AlGaAs/AlAs/GaAs stack, with the advantage that the top layer remains single-crystalline. The thick film oxidation of AlAs is required for photonic applications. In this article, we report the oxidation processes developed to fully convert AlAs to AlOx films by analyzing both thin (100 nm) and thick (500 nm) AlAs films on GaAs (001) and 2° miscut GaAs (111)A substrate. Systematic microscopic characterization is performed to demonstrate the absence of any delamination at the oxide interfaces and the evolution of the diffusive oxidation process microscopically characterized is compared with an optical (µ-Raman) characterization. We demonstrate the selectivity of the AlAs oxidation process with respect to the active Al0....
Metasurfaces are versatile tools for manipulating light; however, they have received little atten... more Metasurfaces are versatile tools for manipulating light; however, they have received little attention as devices for the efficient control of nonlinearly diffracted light. Here, we demonstrate nonlinear wavefront control through third-harmonic generation (THG) beaming into diffraction orders with efficiency tuned by excitation of hybrid Mie−quasi-bound states in the continuum (BIC) modes in a silicon metasurface. Simultaneous excitation of the high-Q collective Mie-type modes and quasi-BIC modes leads to their hybridization and results in a local electric field redistribution. We probe the hybrid mode by measuring far-field patterns of THG and observe the strong switching between (0,−1) and (−1,0) THG diffraction orders from 1:6 for off-resonant excitation to 129:1 for the hybrid mode excitation, showing tremendous contrast in controlling the nonlinear diffraction patterns. Our results pave the way to the realization of metasurfaces for novel light sources, telecommunications, and quantum photonics.
2021 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), 2021
Hot electron-based devices are quite promissing for ultrafast photodetection and to set off enhan... more Hot electron-based devices are quite promissing for ultrafast photodetection and to set off enhanced physicochemical reactions [1] . Controlling their generation at the nanoscale within plasmonic devices is a key for the future development of hybrid hot-electrons technologies. Indeed, Surface Plasmon-Polaritons (SPPs) can be exploited to confine light and enhance the number of excited hot carriers [2] . We aim at studying the excitation and dynamics of hot electrons, enhanced by plasmonics, with two different approaches.
We report on a systematic analysis of phosphorus diffusion in silicon on insulator thin film via ... more We report on a systematic analysis of phosphorus diffusion in silicon on insulator thin film via spin-on-dopant process (SOD). This method is used to provide an impurity source for semiconductor junction fabrication. The dopant is first spread into the substrate via SOD and then diffused by a rapid thermal annealing process. The dopant concentration and electron mobility were characterized at room and low temperature by four-probe and Hall bar electrical measurements. Time-of-flight-secondary ion mass spectroscopy was performed to estimate the diffusion profile of phosphorus for different annealing treatments. We find that a high phosphorous concentration (greater than 1020 atoms cm−3) with a limited diffusion of other chemical species and allowing to tune the electrical properties via annealing at high temperature for short time. The ease of implementation of the process, the low cost of the technique, the possibility to dope selectively and the uniform doping manufactured with sta...
We demonstrate the feasibility of growing GaAs nanomembranes on a plastically-relaxed Ge layer de... more We demonstrate the feasibility of growing GaAs nanomembranes on a plastically-relaxed Ge layer deposited on Si (111) by exploiting selective area epitaxy in MBE. Our results are compared to the case of the GaAs homoepitaxy to highlight the criticalities arising by switching to heteroepitaxy. We found that the nanomembranes evolution strongly depends on the chosen growth parameters as well as mask pattern. The selectivity of III-V material with respect to the SiO2 mask can be obtained when the lifetime of Ga adatoms on SiO2 is reduced, so that the diffusion length of adsorbed Ga is high enough to drive the Ga adatoms towards the etched slits. The best condition for a heteroepitaxial selective area epitaxy is obtained using a growth rate equal to 0.3 ML/s of GaAs, with a As BEP pressure of about 2.5 × 10−6 torr and a temperature of 600 °C.
No further publication processing will occur until we receive your response to this proof. Attach... more No further publication processing will occur until we receive your response to this proof. Attached is a PDF proof of your forthcoming article in Physical Review Materials. Your article has 8 pages and the Accession Code is ME10125. Please note that as part of the production process, APS converts all articles, regardless of their original source, into standardized XML that in turn is used to create the PDF and online versions of the article as well as to populate third-party systems such as Portico, Crossref, and Web of Science. We share our authors' high expectations for the fidelity of the conversion into XML and for the accuracy and appearance of the final, formatted PDF. This process works exceptionally well for the vast majority of articles; however, please check carefully all key elements of your PDF proof, particularly any equations or tables.
We demonstrate the use of plasmonic effects to boost the near-infrared sensitivity of metal-semic... more We demonstrate the use of plasmonic effects to boost the near-infrared sensitivity of metal-semiconductor-metal detectors. Plasmon-enhanced photodetection is achieved by properly optimizing Au interdigitated electrodes, micro-fabricated on Ge, a semiconductor that features a strong near IR absorption. Finite-difference time-domain simulations, photocurrent experiments and Fourier-transform IR spectroscopy are performed to validate how a relatively simple tuning of the contact geometry allows for an enhancement of the response of the device adapting it to the specific detection needs. A 2-fold gain factor in the Ge absorption characteristics is experimentally demonstrated at 1.4 µm, highlighting the potential of this approach for optoelectronic and sensing applications.
Buried-channel semiconductor heterostructures are an archetype material platform to fabricate gat... more Buried-channel semiconductor heterostructures are an archetype material platform to fabricate gated semiconductor quantum devices. Sharp confinement potential is obtained by positioning the channel near the surface, however nearby surface states degrade the electrical properties of the starting material. In this paper we demonstrate a two-dimensional hole gas of high mobility (5 × 10 5 cm 2 /Vs) in a very shallow strained germanium channel, which is located only 22 nm below the surface. This high mobility leads to mean free paths ≈ 6µm, setting new benchmarks for holes in shallow FET devices. Carriers are confined in an undoped Ge/SiGe heterostructure with reduced background contamination, sharp interfaces, and high uniformity. The top-gate of a dopant-less field effect transistor controls the carrier density in the channel. The high mobility, along with a percolation density of 1.2 × 10 11 cm −2 , light effective mass (0.09 me), and high g-factor (up to 7) highlight the potential of undoped Ge/SiGe as a low-disorder material platform for hybrid quantum technologies. Recently, Ge/SiGe heterostructures have emerged as a
A novel scanning probe tip made of heavily doped semiconductor is fabricated and used instead of ... more A novel scanning probe tip made of heavily doped semiconductor is fabricated and used instead of standard gold-coated tips in infrared scattering-type near-field microscopy. Mid-infrared near-field microscopy experiments were conducted on ZnO nanowires with a lateral resolution better than 100 nm, using tips made of heavily electrondoped germanium with plasma frequency in the mid-infrared (plasma wavelength of 9.5 μm). Nanowires embedded in a dielectric matrix were imaged at two wavelengths, 11.3 μm and 8.0 μm, above and below the plasma wavelength of the tips. An opposite sign of the imaging contrasts between the nanowire and the dielectric matrix was observed at the two infrared wavelengths, indicating a clear role of the free electron plasma in the heavily doped germanium tip in building the imaging contrast. Electromagnetic simulations with a multi-spherical dipole model accounting for the finite size of the tip are well consistent with the experiments. By comparison of the simulated and measured imaging contrasts, an estimate for the local free carrier density in the investigated ZnO nanowires in the low 10 19 cm-3 range is retrieved. The results are benchmarked against the scattering intensity and phase maps obtained on the same sample with a goldcoated probe tip in pseudo-heterodyne detection mode.
Dewetting is a ubiquitous phenomenon in nature; many different thin films of organic and inorgani... more Dewetting is a ubiquitous phenomenon in nature; many different thin films of organic and inorganic substances (such as liquids, polymers, metals, and semiconductors) share this shape instability driven by surface tension and mass transport. Via templated solid-state dewetting, we frame complex nanoarchitectures of monocrystalline silicon on insulator with unprecedented precision and reproducibility over large scales. Phase-field simulations reveal the dominant role of surface diffusion as a driving force for dewetting and provide a predictive tool to further engineer this hybrid top-down/bottom-up self-assembly method. Our results demonstrate that patches of thin monocrystalline films of metals and semiconductors share the same dewetting dynamics. We also prove the potential of our method by fabricating nanotransfer molding of metal oxide xerogels on silicon and glass substrates. This method allows the novel possibility of transferring these Si-based patterns on different materials,...
We discuss a new type of nanoscale photon source constituted by a micro-pyramid made of epitaxial... more We discuss a new type of nanoscale photon source constituted by a micro-pyramid made of epitaxial semiconductor material (Ge) attached to a silicon cantilever optimized for Atomic Force Microscopy and shaped by means of low-current Focused Ion Beam (FIB) milling.. The optical characterization of these tips demonstrates sizeable photoluminescence emission at the direct energy gap of Ge (1550 nm). We have checked by independent measurements on the nano-patterned epitaxial material prior to the tip shaping process that the photoluminescence yield is not significantly affected by FIB milling, indicating that the optical properties of the material in this wavelength range are preserved. We envisage an application of this tool as a scanning probe in apertureless scanning near-field optical microscopy. High-resolution optical imaging has become a fundamental tool in nanoscience and nanotechnology and is playing a key role in physical sciences, biology, medicine and telecommunications. The majority of far-field optical microscopy techniques are extensively used for imaging biological samples, but they hardly overcome light diffraction, setting a limit to the lateral resolution that is slightly below the optical wavelength (0.4 to 1.5 m
In this work we address optical orientation, a process consisting in the excitation of spin polar... more In this work we address optical orientation, a process consisting in the excitation of spin polarized electrons across the gap of a semiconductor. We show that the combination of optical orientation with spin-dependent scattering leading to the inverse spin-Hall effect, i.e., to the conversion of a spin current into an electrical signal, represents a powerful tool to generate and detect spin currents in solids. We consider a few examples where these two phenomena together allow addressing the spin-dependent transport properties across homogeneous samples or metal/semiconductor Schottky junctions.
Uploads
Papers by Monica Bollani