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A novel silicon heterojunction IBC process flow using partial etching of doped a-Si:H to switch from hole contact to electron contact <i>in situ</i> with efficiencies close to 23%
摘要: We present a novel process sequence to simplify the rear‐side patterning of the silicon heterojunction interdigitated back contact (HJ IBC) cells. In this approach, interdigitated strips of a‐Si:H (i/p+) hole contact and a‐Si:H (i/n+) electron contact are achieved by partially etching a blanket a‐Si:H (i/p+) stack through an SiOx hard mask to remove only the p+ a‐Si:H layer and replace it with an n+ a‐Si:H layer, thereby switching from a hole contact to an electron contact in situ, without having to remove the entire passivation. This eliminates the ex situ wet clean after dry etching and also prevents re‐exposure of the crystalline silicon surface during rear‐side processing. Using a well‐controlled process, high‐quality passivation is maintained throughout the rear‐side process sequence leading to high open‐circuit voltages (VOC). A slightly higher contact resistance at the electron contact leads to a slightly higher fill factor (FF) loss due to series resistance for cells from the partial etch route, but the FF loss due to J02‐type recombination is lower, compared with reference cells. As a result, the best cell from the partial etch route has an efficiency of 22.9% and a VOC of 729 mV, nearly identical to the best reference cell, demonstrating that the developed partial etch process can be successfully implemented to achieve cell performance comparable with reference, but with a simpler, cheaper, and faster process sequence.
关键词: interdigitated back contact (IBC),H2 plasma,amorphous silicon,heterojunction,dry etch,process simplification,NF3/Ar plasma,in situ processing
更新于2025-09-23 15:23:52
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Unidirectional light scattering by up–down Janus dimers composed of gold nanospheres and silicon nanorods
摘要: In this paper, a time-domain finite-difference (FDTD) method is used to simulate the scattering properties of a Janus dimer that a gold nanosphere is putted on the top of a silicon nanorod. We have demonstrated that the Janus dimer exhibits unidirectional scattering in the whole wavelength region of the sunlight. The unidirectionality of the dimer will improve with the height increase of the silicon nanorod and the gap decrease between two adjacent dimers. In our simulation, the forward-to-backward ratio (F/B) of the Janus dimer calculated dividing forward scattering spectra by backward scattering spectra can achieve the maximum of 20 when the height of silicon nanorod is 300 nm. What is more, we have applied the Janus dimers to amorphous silicon thin-film solar cells as antireflection structures. The reflectivity of the solar cells reduces by 39.40% and the short circuit current density improves by 5.04% than those of the reference. Therefore, the Janus dimers has a great application prospect in photovoltaic devices.
关键词: Amorphous silicon solar cells,Janus dimers,Unidirectional scattering,Electric and magnetic dipole resonance
更新于2025-09-23 15:23:52
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Amorphous silicon and silicates-stabilized ZrO2 hollow fiber with low thermal conductivity and high phase stability derived from a cogon template
摘要: ZrO2 ?bers are used as refractory materials owing to their excellent thermal resistance and thermal stability. Natural cogon ?ber is a type of hollow Gramineae ?ber, and usually contains a small amount of amorphous silicon and silicates, such as SiO2, MgSiO3, CaSiO4, and Al2SiO5, which can e?ectively avoid the phase transition of ZrO2. In this study, hollow ZrO2 ?bers with remarkable thermal insulation and phase stability were synthesized using a cogon ?ber template. The results showed that the ?nal ZrO2 ?bers successfully inherited the hollow structure and amorphous substance from the cogon template. The hollow structure of the biomorphic ZrO2 ?ber helped prevent heat ?ow more e?ciently compared to solid ?bers and reduced the thermal conductivity to a signi?cant extent. In addition, the amorphous silicon and silicates played an important role in the phase stability of tetragonal ZrO2; the transformation from the tetragonal to monoclinic phase was avoided at room temperature and in humid environment.
关键词: Thermal conductivity,Amorphous silicon and silicates,Cogon ?bers,Phase stability,ZrO2 hollow ?bers
更新于2025-09-23 15:23:52
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Li Permeability Increase in Nano-Sized Amorphous Silicon Layers
摘要: Li permeation through nano-sized amorphous Si layers is investigated for temperatures up to 500°C (773 K) as a function of layer thickness between 12 and 95 nm. For the experiments the Si layers are embedded between 6Li and 7Li isotope enriched oxide based Li reservoirs and the thermally induced isotope exchange (through silicon layers and interfaces) is analyzed by Secondary Ion Mass Spectrometry in order to calculate Li permeabilities. The experiments reveal that the interface between silicon and the Li metal oxide does not hinder Li permeation and Li diffusion in silicon controls the overall process. The determined Li permeability increases drastically by orders of magnitude with decreasing silicon layer thickness, accompanied by a decrease in the activation enthalpy of Li permeation. These results can be explained by a gradual transition of trap-limited slow Li diffusion at high silicon thicknesses to interstitial fast Li diffusion at low Si thicknesses.
关键词: Li permeation,nano-sized layers,Li permeability,trap-limited diffusion,amorphous silicon,Secondary Ion Mass Spectrometry,isotope exchange,interstitial diffusion
更新于2025-09-23 15:21:21
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Transparent Thin-Film Silicon Solar Cells for Indoor Light Harvesting with Conversion Efficiencies of 36% without Photo-degradation
摘要: With the development of the Internet of Things (IoT), indoor photovoltaics are attracting considerable interest owing to their potential to benefit various IoT-related fields. Therefore, this study investigates the use of transparent hydrogenated amorphous silicon (a-Si:H) solar cells for a broad range of applications, including indoor light harvesting. High gap triple-layers were employed in the a-Si:H solar cells to obtain a high shunt resistance and high short-circuit current, JSC, and open-circuit voltage, VOC, under indoor illumination. Additionally, multiple color-adjusting layers were added without noticeable costs to the conversion efficiency. The maximum efficiency of 36.0% was obtained at a transmittance of 20.44% under white LED light (3,000 lx and 0.92 mW cm-2). Furthermore, the fabricated transparent solar cells show excellent long-term performance, sustaining over 99% of original efficiency under continuous indoor light illumination for 200 h. These cells could accelerate the progress of energy harvesting in IoT applications and facilitate the construction of integrated photovoltaics.
关键词: amorphous silicon solar cells,thin film silicon solar cells,transparent solar cells,indoor photovoltaics,colored solar cells
更新于2025-09-23 15:21:01
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Damp-Heat-Stable, High-Efficiency, Industrial-Size Silicon Heterojunction Solar Cells
摘要: Silicon heterojunction (SHJ) solar cells hold the power conversion efficiency (PCE) record among crystalline solar cells. However, amorphous silicon is a typical high-entropy metastable material. Damp-heat aging experiments unveil that the amorphous/crystalline silicon interface is susceptible to moisture, which is potentially the biggest stumbling block for mass production. By capping SiNx and SiOx dielectrics, the absolute PCE degradation is predicted to be only (cid:1)0.6% after a 30-year installation. This demonstrates the SHJ solar cell is a highly promising candidate for next-generation photovoltaics.
关键词: High efficiency,Amorphous silicon,Mass production,Damp-heat stability,Silicon heterojunction solar cells
更新于2025-09-23 15:21:01
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Efficient broadband light absorption in thin-film a-Si solar cell based on double sided hybrid bi-metallic nanogratings
摘要: Thin film solar cells (TFSCs) suffer from poor light absorption due to their small thickness, which limits most of their practical applications. Surface plasmons generated by plasmonic nanoparticles offer an opportunity for a low-cost and scalable method to optically engineer TFSCs. Here, a systematic simulation study is conducted to improve the absorption efficiency of amorphous silicon (a-Si) by incorporating double sided plasmonic bi-metallic (Al–Cu) nanogratings. The upper pair of the gratings together with an antireflection coating are responsible for minimizing the reflection losses and enhancing the absorption of low wavelength visible light spectrum in the active layer. The bottom pairs are accountable for increasing the absorption of long wavelength photons in the active layer. In this way, a-Si, which is a poor absorber in the long wavelength region, is now able to absorb broadband light from 670–1060 nm with an average simulated absorption rate of more than 70%, and improved simulated photocurrent density of 22.30 mA cm?2, respectively. Moreover, simulation results show that the proposed structure reveals many other excellent properties such as small incident angle insensitivity, tunability, and remarkable structural parameters tolerance. Such a design concept is quite versatile and can be extended to other TFSCs.
关键词: amorphous silicon,Thin film solar cells,plasmonic nanoparticles,bi-metallic nanogratings,light absorption
更新于2025-09-23 15:21:01
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Optimization of laser-patterning process and module design for transparent amorphous silicon thin-film module using thin OMO back electrode
摘要: Transparent hydrogenated amorphous silicon thin-film solar modules are fabricated using oxide-metal-oxide (OMO) electrodes as the back electrode for building-integrated photovoltaic applications. The outer aluminum-doped zinc oxide and inner silver layers constitute a thin OMO electrode (~110 nm thick), exhibiting a sheet resistance of 6.8 Ω/□ and an average transmittance of ~88% in the visible range of 400–800 nm. The external quantum efficiency and average transmittance of the cell were investigated for the absorber-layer thickness using the finite-difference time-domain method, and it was found that the optical loss in the cell was mainly due to the absorption of the front electrode in the ultra-violet region and free-carrier absorption of the OMO in the infrared region. Fabrication issues are introduced for a 532 nm short-pulse high-power laser patterning process for transparent modules with thin OMO electrodes. Optimization of the laser power for the P2 and P3 laser processes is demonstrated by observing the profiles and measuring the shunt resistance of the laser-patterned edges. Furthermore, the cell width is optimized based on an equivalent circuit model using PSpice simulation. The highest module efficiency and average transparency achieved in the range of 500–800 nm were 5.6% and 15.2%, respectively. The short-circuit current density, fill factor, and open-circuit voltage per cell of the module were found to be 10.8 mA/cm2, 62.7%, and 0.830 V, respectively.
关键词: Laser patterning,Transparent amorphous silicon photovoltaic,Equivalent circuit,Building integrated photovoltaic,Cell geometry,Oxide-metal-oxide electrode
更新于2025-09-23 15:21:01
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Amorphous Silicon with Extremely Low Absorption: Beating Thermal Noise in Gravitational Astronomy
摘要: Amorphous silicon has ideal properties for many applications in fundamental research and industry. However, the optical absorption is often unacceptably high, particularly for gravitational-wave detection. We report a novel ion-beam deposition method for fabricating amorphous silicon with unprecedentedly low unpaired electron-spin density and optical absorption, the spin limit on absorption being surpassed for the first time. At low unpaired electron density, the absorption is no longer correlated with electron spins, but with the electronic mobility gap. Compared to standard ion-beam deposition, the absorption at 1550 nm is lower by a factor of ≈100. This breakthrough shows that amorphous silicon could be exploited as an extreme performance optical coating in near-infrared applications, and it represents an important proof of concept for future gravitational-wave detectors.
关键词: amorphous silicon,thermal noise,gravitational-wave detection,ion-beam deposition,optical absorption
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Angular Dependence of Textured Bifacial Silicon Heterojunction Solar Cells for High Latitudes
摘要: Bifacial photovoltaics at high latitudes can achieve up to 25-45% bifacial gain due to high-albedo snow cover and high proportion of diffuse light. We studied the angular performance of bifacial silicon heterojunction solar cells with various textures to understand high-latitude effects on optical losses. For cone and pyramid-patterned designs, efficiency decreases at high angles, primarily due to increased reflectivity, although longer path length through front-surface films also increases UV losses for all surface types. At 80° incidence and 25°C, a <7% reduction in short-circuit current due to change in external quantum efficiency is observed for random pyramid textured surfaces. Simulation is compared to measured external quantum efficiency for a silicon heterojunction cell, and similar trends are observed with increasing angle of incidence. A relative reduction of <1% in short-circuit current is also observed when moving from an air mass of 1.5 to 5 at high angles of incidence. These results will inform future solar heterojunction designs for this application and be applied to refine annual energy yield calculations.
关键词: photovoltaic cells,bifacial photovoltaics,indium-tin-oxide,amorphous silicon,ray tracing,silicon solar cell,texture,angle of incidence,heterojunction cell,air mass
更新于2025-09-23 15:19:57