- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
AIP Conference Proceedings [Author(s) SILICONPV 2018, THE 8TH INTERNATIONAL CONFERENCE ON CRYSTALLINE SILICON PHOTOVOLTAICS - Lausanne, Switzerland (19–21 March 2018)] - Understanding the optics of industrial black silicon
摘要： Industrial scale black silicon texturing has become a topic of increasing importance as a method for enabling lower cost multicrystalline silicon wafers through diamond wire sawing, as well as for its potential to provide improved efficiencies through enhanced optical characteristics. Two different texturing processes have emerged as candidates for mainstream industrial uptake, metal catalyzed chemical etching (MCCE) and reactive ion etching (RIE). However, these techniques can produce substantially different textures and both provide a wide parameter space allowing for various feature shapes and sizes to be produced. The surface texture not only determines the total reflectance of a solar cell, but also impacts the light trapping and subsequent absorption through scattering. Here, we carry out a detailed analysis on a representative range of both MCCE and RIE textures on multiple substrate types in order to further develop the fundamental understanding of how these specific surface morphologies impact the optical characteristics. This will better enable integration with other process conditions as well as optimization between optical and electrical requirements.
关键词： black silicon,surface morphology,RIE,MCCE,optical characteristics
更新于2025-10-22 19:40:53
-
Influence of diamond tool chamfer angle on surface integrity in ultra-precision turning of singe crystal silicon
摘要： Ultra precision diamond machining enables the economical production of freeform optics on infrared materials such as silicon. To produce optics with acceptable surface integrity, it is important to have a good understanding of process-work material interaction between diamond tool and brittle and hard single crystal IR materials. Chamfered cutting edges are known to have high strength, which makes them suitable for machining difficult-to-cut materials. This study investigates the influence of chamfer angle on the surface integrity of silicon. Diamond tool chamfer angles of ? 20°, ? 30°, and ? 45° are considered under practical diamond turning conditions of single crystal silicon. State-of-the-art techniques were used to investigate the surface integrity of the machined silicon surfaces. The results show that chamfer angle of 30° yields more favorable results compared to 20° and 45° under the conditions tested. The results indicate the complex interplay between tool geometry and process parameters in reaching an acceptable level of surface integrity. A machinability map indicating ductile and brittle machining conditions for 30° chamfered diamond tool has been presented which includes directly transferable knowledge to the precision machining industry.
关键词： Silicon,Surface integrity,Phase transformation,Diamond machining
更新于2025-09-23 15:21:21
-
Theory of atomic scale quantum dots in silicon: Dangling bond quantum dots on silicon surface
摘要： We present a theory and a computational tool, Silicon-Qnano, describing atomic scale quantum dots in silicon. The developed methodology is applied to model dangling bond quantum dots (DBQDs) created on a passivated H:Si-(100)-(2×1) surface by removing a hydrogen atom. The electronic properties of the DBQD are computed by embedding it in a computational box of silicon atoms. The surfaces of the computational box were constructed by using density functional theory as implemented in the Abinit package. The top layer was reconstructed by the formation of Si dimers passivated with H atoms while the bottom layer remained unreconstructed and fully saturated with H atoms. The computational box Hamiltonian was approximated by a tight-binding (TB) Hamiltonian by expanding the electron wave functions as linear combinations of atomic orbitals and fitting the band structure to ab-initio results. The parametrized TB Hamiltonian was used to model large finite Si(100) boxes (slabs) with number of atoms exceeding present capabilities of ab-initio calculations. The removal of one hydrogen atom from the reconstructed surface resulted in a DBQD state with a wave function strongly localized around the Si atom and the energy in the silicon band gap. The DBQD could be charged with zero, one, and two electrons. The Coulomb matrix elements were calculated and the charging energy of a two electron complex in a DBQD obtained.
关键词： A. Silicon surface,D. Tight-binding model,D. Dangling bonds,A. Semiconductors
更新于2025-09-16 10:30:52
-
Cylindrical and plane surface electromagnetic waves in laser technology of silicon surface texturing with a double femtosecond pulse
摘要： This paper presents experimental results of laser modification of the surface of monocrystalline silicon under the influence of a double femtosecond laser pulse with varying delays less than or close to the electron–phonon interaction time, as well as the results of numerical simulation of the photoexcitation of a semiconductor in the approximation of dielectric constant. It is shown that the excitation of cylindrical surface waves not only precedes the excitation of plane surface electromagnetic waves, but is also a determining factor in the cumulative change in the dielectric constant of the medium and the creation of conditions for the excitation of plane surface electromagnetic waves.
关键词： Femtosecond texturing of the surface,Cylindrical surface electromagnetic waves,Monocrystalline silicon,Surface electromagnetic waves,Double femtosecond laser pulse
更新于2025-09-11 14:15:04
-
In-situ Process to Form Passivated Tunneling Oxides for Front-surface Field in Rear-emitter Silicon Heterojunction Solar Cells
摘要： A novel approach involving CO2 plasma treatment of intrinsic hydrogenated amorphous silicon was developed to form ultra-thin silicon oxide (SiOx) layers, that is, passivated tunneling layers (PTLs), for the fabrication of passivated tunneling contacts. These contacts were formed by depositing the PTL/n-type hydrogenated nano-crystalline layer (nc-Si:H(n))/c-Si(n) stacks. The results indicated that a higher CO2 plasma treatment pressure was preferred for the formation of oxygen-richer components in the silicon oxide films, with Si2+, Si3+, and Si4+ peaks, and a smoother PTL/c-Si heterointerface. The PTLs with higher oxidation states and lower surface roughness exhibited advantages for the c-Si surface passivation, with a maximum implied open-circuit voltage of approximately 743 mV. The lowest contact resistivity of approximately 60 mΩcm2 was obtained using nc-Si:H(n)/PTL/c-Si(n) as the passivated tunneling contact. Most importantly, the in-situ process can help prevent the contamination of the heterointerface during device fabrication processes.
关键词： Passivated tunneling layer (PTL),Silicon oxide (SiOx),CO2 plasma treatment,Silicon surface passivation
更新于2025-09-11 14:15:04
-
AIP Conference Proceedings [AIP Publishing 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Fes, Morocco (25–27 March 2019)] 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Low-temperature silicon surface passivation for bulk lifetime studies based on Corona-charged Al2O3
摘要： Bulk lifetime studies of crystalline silicon wafers, e.g. with the aim of studying the light-induced degradation and regeneration behavior, require low-temperature surface passivation schemes that do not alter the silicon bulk properties, e.g. through hydrogenation. Aluminum oxide (Al2O3) can provide an excellent and stable surface passivation, however, in order to achieve the best possible surface passivation, an annealing step at ~400°C is typically required, which has been found to alter the bulk properties of some silicon materials. Hence, in this contribution we examine the possibility of passivating the silicon surface using Al2O3 layers that have seen a much lower thermal budget. We demonstrate that we are able to achieve an excellent silicon surface passivation using atomic-layer-deposited Al2O3 with measured effective surface recombination velocities Seff as low as 1.3 cm/s without exceeding a temperature of 250°C. We are able to achieve such excellent low-temperature passivation by applying a post-deposition annealing step at 250°C in combination with the deposition of negative Corona charges on the Al2O3 surface. For samples annealed at only 220°C, we still reach very low Seff values of 2 cm/s after deposition of negative Corona charges. We demonstrate that the Corona-charged low-temperature Al2O3 passivation shows only a slight degradation from an Seff of 1.6 cm/s to an Seff of 5 cm/s after 218 days of storage. Even without any post-deposition anneal and only negative Corona charges deposited, we achieve stable Seff values of 15 cm/s. As an alternative to Corona charging, a short exposure to intense UV light (λ = 395 nm) also significantly improves the surface passivation quality of low-temperature-annealed Al2O3-passivated silicon samples. However, the best surface passivation for the latter method is limited to an Seff value of 6.6 cm/s, which is still quite reasonable for bulk lifetime studies.
关键词： bulk lifetime studies,Al2O3,Corona charging,silicon surface passivation,low-temperature annealing
更新于2025-09-11 14:15:04
-
Beyond the molecular movie: Dynamics of bands and bonds during a photoinduced phase transition
摘要： Ultrafast nonequilibrium dynamics offer a route to study the microscopic interactions that govern macroscopic behavior. In particular, photoinduced phase transitions (PIPTs) in solids provide a test case for how forces, and the resulting atomic motion along a reaction coordinate, originate from a nonequilibrium population of excited electronic states. Using femtosecond photoemission, we obtain access to the transient electronic structure during an ultrafast PIPT in a model system: indium nanowires on a silicon(111) surface. We uncover a detailed reaction pathway, allowing a direct comparison with the dynamics predicted by ab initio simulations. This further reveals the crucial role played by localized photoholes in shaping the potential energy landscape and enables a combined momentum- and real-space description of PIPTs, including the ultrafast formation of chemical bonds.
关键词： Silicon surface,Photoinduced phase transitions,Chemical bonds,Electronic structure,Indium nanowires,Femtosecond photoemission,Ultrafast dynamics
更新于2025-09-10 09:29:36
-
Landscape of s-triazine molecule on Si(100) by a theoretical x-ray photoelectron spectroscopy and x-ray absorption near-edge structure spectra study
摘要： The chemisorbed structure for an aromatic molecule on a silicon surface plays an important part in promoting the development of organic semiconductor material science. The carbon K-shell x-ray photoelectron spectroscopy (XPS) and the x-ray absorption near-edge structure (XANES) spectra of the interfacial structure of an s-triazine molecule adsorbed on Si(100) surface have been performed by the ?rst principles, and the landscape of the s-triazine molecule on Si(100) surface has been described in detail. Both the XPS and XANES spectra have shown their dependence on different structures for the pristine s-triazine molecule and its several possible adsorbed con?gurations. By comparison with the XPS spectra, the XANES spectra display the strongest structural dependency of all of the studied systems and thus could be well applied to identify the chemisorbed s-triazine derivatives. The exploration of spectral components originated from non-equivalent carbons in disparate local environments has also been implemented for both the XPS and XANES spectra of s-triazine adsorbed con?gurations.
关键词： silicon surface,x-ray absorption near-edge structure (XANES),x-ray photoelectron spectroscopy (XPS),s-triazine
更新于2025-09-09 09:28:46
-
SENSING IMMOBILIZED MOLECULES OF STREPTAVIDIN ON A SILICON SURFACE BY MALDI-TOF MASS SPECTROMETRY AND FLUORESCENCE MICROSCOPY
摘要： A hydrogen-terminated Si (111) surface was modified to form an aminoterminated monolayer for immobilization of streptavidin. Cleavage of an N-(ω-undecylenyl)-phthalimide covered surface using hidrazine yields an amino group-modified surface, which serves as a substrate for the attachment of biotin and subsequently streptavidin. We used surface analytical techniques to characterize the surface and to control the course of functionalization before the immobilization of streptavidin. To confirm the presence of the streptavidin Texas red on the surface two powerful techniques available in a standard biochemical laboratory are used, Fluorescence Microscopy and MALDI-TOF that allow us to detect and determine the immobilized streptavidin. This work provides an avenue for the development of devices in which the exquisite binding specificity of biomolecular recognition is directly coupled to a biosensor. In addition, we have demonstrated that MALDI-TOF and fluorescence microscopy are useful techniques for the characterization of silicon functionalized surfaces.
关键词： streptavidin,fluorescence microscopy,MALDI-TOF,biosensor,silicon surface
更新于2025-09-04 15:30:14