In the present paper, some novel opportunities for the development of high-efficient Si and III-V-based solar cells are considered: energy-saving environment friendly low-temperature technology of forming p-n junction...In the present paper, some novel opportunities for the development of high-efficient Si and III-V-based solar cells are considered: energy-saving environment friendly low-temperature technology of forming p-n junctions in Si (1), elaboration of structurally perfect GaAs/Ge/Si epitaxial substrates (2) and application of protective antireflecting coatings based on cubic zirconia (3). As a result: 1) New technique of forming p-n junctions in silicon has been elaborated. The technique provided easy and comparatively cheap process of production of semiconductor devices such as solar cells. The essence of the technique under the study is comprised in formation p-n junctions in silicon by a change of conductivity in the bulk of the sample occurring as a result of redistribution of the impurities, which already exists in the sample before its processing by ions. It differs from the techniques of diffusion and ion doping where change of conductivity and formation of p-n junction in the sample occur as a result of introduction of atoms of the other dopants from the outside;2) The conditions for synthesis of GaAs/Ge/Si epitaxial substrates with a thin (200 nm) Ge buffer layer featured with (1 - 2) × 105 cm-2 density of the threading dislocation in the GaAs layer. Ge buffer was obtained by chemical vapor deposition with a hot wire and GaAs layer of 1 μm thick was grown by the metal organic chemical vapor deposition. Root mean square surface roughness of GaAs layers of the less than 1 nm and good photoluminescence properties along with their high uniformity were obtained;3) The conditions ensuring the synthesis of uniform functional (buffer, insulating and protective) fianite layers on Si and GaAs substrates by means of magnetron and electron-beam sputtering have been determined. Fianite films have been shown to be suitable for the use as an ideal anti-reflecting material with high protective and anticorrosive properties.展开更多
We demonstrate monolithically integrated n-GaAs/p-Si depletion-type optical phase shifters fabricated on a 300 mm wafer-scale Si photonics platform.We measured the phase shifter performance using Mach–Zehnder modulat...We demonstrate monolithically integrated n-GaAs/p-Si depletion-type optical phase shifters fabricated on a 300 mm wafer-scale Si photonics platform.We measured the phase shifter performance using Mach–Zehnder modulators with the GaAs/Si optical phase shifters in both arms.A modulation efficiency of V_(π)L as low as 0.3 V·cm has been achieved,which is much lower compared to a carrier-depletion type Si optical phase shifter with pn junction.While propagation loss is relatively high at.5 d B∕mm,the modulator length can be reduced by the factor of.2 for the same optical modulation amplitude of a Si reference Mach–Zehnder modulator,owing to the high modulation efficiency of the shifters.展开更多
To explain different doping effects in a buffer layer,thermally annealed interface,and upper epilayers of GaAs/Si films grown by Metalorganic Chemical Vapor Deposition(MOCVD),the behaviors of unintentional doping in G...To explain different doping effects in a buffer layer,thermally annealed interface,and upper epilayers of GaAs/Si films grown by Metalorganic Chemical Vapor Deposition(MOCVD),the behaviors of unintentional doping in GaAs/Si films are investigated in detail.A third doping mechanism of arsine impurity incorporation during the growth process of GaAs/Si films,apart from conventional mechanisms of gas phase reaction and diffusion from the silicon substrate,is proposed.The experimental results reveal that the doping behavior in the buffer layer studied is determined by the three types of doping mechanisms together.However in the thermally annealed interface and upper epilayers,the third doping mechanism is dominant.According to the third mechanism,the background carrier concentration in GaAs/Si films grown by MOCVD could be properly controlled through the arsine flow rate.展开更多
We report a novel technique for growing high-quality GaAs on Si substrate.The process involves deposition of a thin amorphous Si film prior to the conventional two-step growth.The GaAs layers grown on Si by this techn...We report a novel technique for growing high-quality GaAs on Si substrate.The process involves deposition of a thin amorphous Si film prior to the conventional two-step growth.The GaAs layers grown on Si by this technique using metalorganic chemical vapor deposition exhibit a better surface morphology and higher crystallinity as compared to the samples grown by conventional two-step method.The full width at half maximum(FWHM)of the x-ray(004)rocking curve for 2.2 μm thick GaAs/Si epilayer grown by using this new method is 160 arcsec.The FWHM of the photoluminescence spectrum main peak for this sample is 2.1 meV.These are among the best results reported so far.In addition,the mechanism of this new growth method was studied using high-resolution transmission electron microscopy.展开更多
文摘In the present paper, some novel opportunities for the development of high-efficient Si and III-V-based solar cells are considered: energy-saving environment friendly low-temperature technology of forming p-n junctions in Si (1), elaboration of structurally perfect GaAs/Ge/Si epitaxial substrates (2) and application of protective antireflecting coatings based on cubic zirconia (3). As a result: 1) New technique of forming p-n junctions in silicon has been elaborated. The technique provided easy and comparatively cheap process of production of semiconductor devices such as solar cells. The essence of the technique under the study is comprised in formation p-n junctions in silicon by a change of conductivity in the bulk of the sample occurring as a result of redistribution of the impurities, which already exists in the sample before its processing by ions. It differs from the techniques of diffusion and ion doping where change of conductivity and formation of p-n junction in the sample occur as a result of introduction of atoms of the other dopants from the outside;2) The conditions for synthesis of GaAs/Ge/Si epitaxial substrates with a thin (200 nm) Ge buffer layer featured with (1 - 2) × 105 cm-2 density of the threading dislocation in the GaAs layer. Ge buffer was obtained by chemical vapor deposition with a hot wire and GaAs layer of 1 μm thick was grown by the metal organic chemical vapor deposition. Root mean square surface roughness of GaAs layers of the less than 1 nm and good photoluminescence properties along with their high uniformity were obtained;3) The conditions ensuring the synthesis of uniform functional (buffer, insulating and protective) fianite layers on Si and GaAs substrates by means of magnetron and electron-beam sputtering have been determined. Fianite films have been shown to be suitable for the use as an ideal anti-reflecting material with high protective and anticorrosive properties.
基金IMEC’s industry affiliation R&D program,National Research Foundation of KoreaMinistry of Science and ICT,South Korea(2021R1G1A1091912)。
文摘We demonstrate monolithically integrated n-GaAs/p-Si depletion-type optical phase shifters fabricated on a 300 mm wafer-scale Si photonics platform.We measured the phase shifter performance using Mach–Zehnder modulators with the GaAs/Si optical phase shifters in both arms.A modulation efficiency of V_(π)L as low as 0.3 V·cm has been achieved,which is much lower compared to a carrier-depletion type Si optical phase shifter with pn junction.While propagation loss is relatively high at.5 d B∕mm,the modulator length can be reduced by the factor of.2 for the same optical modulation amplitude of a Si reference Mach–Zehnder modulator,owing to the high modulation efficiency of the shifters.
基金Supported by the Fundamental Research Funds for the Central University under Grant No 2013RC1205the National Basic Research Program of China under Grant No 2010CB327602。
文摘To explain different doping effects in a buffer layer,thermally annealed interface,and upper epilayers of GaAs/Si films grown by Metalorganic Chemical Vapor Deposition(MOCVD),the behaviors of unintentional doping in GaAs/Si films are investigated in detail.A third doping mechanism of arsine impurity incorporation during the growth process of GaAs/Si films,apart from conventional mechanisms of gas phase reaction and diffusion from the silicon substrate,is proposed.The experimental results reveal that the doping behavior in the buffer layer studied is determined by the three types of doping mechanisms together.However in the thermally annealed interface and upper epilayers,the third doping mechanism is dominant.According to the third mechanism,the background carrier concentration in GaAs/Si films grown by MOCVD could be properly controlled through the arsine flow rate.
文摘We report a novel technique for growing high-quality GaAs on Si substrate.The process involves deposition of a thin amorphous Si film prior to the conventional two-step growth.The GaAs layers grown on Si by this technique using metalorganic chemical vapor deposition exhibit a better surface morphology and higher crystallinity as compared to the samples grown by conventional two-step method.The full width at half maximum(FWHM)of the x-ray(004)rocking curve for 2.2 μm thick GaAs/Si epilayer grown by using this new method is 160 arcsec.The FWHM of the photoluminescence spectrum main peak for this sample is 2.1 meV.These are among the best results reported so far.In addition,the mechanism of this new growth method was studied using high-resolution transmission electron microscopy.
