Lightweight amorphous silicon photovoltaic modules on flexible plastic substrate

Solar cells on lightweight and flexible substrates have advantages over glass-or wafer-based photovoltaic devices in both terrestrial and space applications. Here, we report on development of amorphous silicon thin film photovoltaic modules fabricated at maximum deposition temperature of 150 degrees C on 100 mu m thick polyethylene-naphtalate plastic films. Each module of 10 cm x 10 cm area consists of 72 a-Si:H n-i-p rectangular structures with transparent conducting oxide top electrodes with Al fingers and metal back electrodes deposited through the shadow masks. Individual structures are connected in series forming eight rows with connection ports provided for external blocking diodes. The design optimization and device performance analysis are performed using a developed SPICE model

Lightweight amorphous silicon photovoltaic modules on flexible plastic substrate

Solar cells on lightweight and flexible substrates have advantages over glass-or wafer-based photovoltaic devices in both terrestrial and space applications. Here, we report on development of amorphous silicon thin film photovoltaic modules fabricated at maximum deposition temperature of 150 degrees C on 100 mu m thick polyethylene-naphtalate plastic films. Each module of 10 cm x 10 cm area consists of 72 a-Si:H n-i-p rectangular structures with transparent conducting oxide top electrodes with Al fingers and metal back electrodes deposited through the shadow masks. Individual structures are connected in series forming eight rows with connection ports provided for external blocking diodes. The design optimization and device performance analysis are performed using a developed SPICE model

Mössbauer studies of structural properties and electrochemical characteristics of LiFePO 4

The valency state and local coordination of Fe ions of four industrial samples and a sample of cathodic materials for recharcheable lithium ion batteries obtained using an original technology of St. Petersburg State Technological Institute (Technological University) were studied using the Mössbauer effect on the 57Fe isotope. It was found that the main valency state for more than 90% of iron ions was Fe 2+. The values of isomer shift δ = 0.96-0.98 mm/s and quadrupole splitting σ = 2.88-2.93 mm/s for Fe 2+ ions coincide with the values for compounds with the structure of olivine LiFePO 4 and occupy positions in highly distorted FeO 6 octahedrons. Fe 3+ ions are in octahedral and/or tetrahedral local positions. © 2012 Pleiades Publishing, Ltd

Тонкие пленки аморфного гидрогенизированного кремния и солнечные модули на их основе

Solar energy is one of the most promising sectors of renewable energy. In Russia the mass development of solar energy in connection with the organization launched in February 2015 at "Hevel" production of thin film solar modules based on amorphous silicon, which is intended to create a full-fledged high-tech industry of solar energy as an alternative to traditional energy sources. For support and development of this production open JSC "Scientific and technical center of thin film technology" begin operation at the Ioffe Institute of RAS in 2012, whose main task - improvement of the basic parameters of Solar modules based on amorphous silicon in the interests of "Hevel".Солнечная энергетика является одной из самых перспективных отраслей возобновляемой энергетики. В России массовое развитие солнечной энергетики связано с организацией запущенного в феврале 2015 г. на ООО "Хевел" производства тонкопленочных солнечных модулей на основе аморфного кремния, которое призвано создать полноценную высокотехнологичную отрасль солнечной энергетики как альтернативу традиционным источникам энергии. Для поддержки и развития этого производства при Физико-техническом институте им. А. Ф. Иоффе в 2012 г. начало функционировать ООО "Научно-технический центр тонкопленочных технологий", главная задача которого - улучшение основных параметров солнечных модулей на основе аморфного кремния в интересах ООО "Хевел"

Optimization and Fabrication of Heterojunction Silicon Solar Cells Using an Experimental-Industrial Facility AK-1000 Inline

Introduction. Heterojunction silicon solar cells represent one of the most promising directions for the development of solar photovoltaics. This is due to both their high power conversion efficiency and reasonable likelihood for further growth in performance, as well as good commercial potential of this technology, which relies on a transition from conventional diffusion-based processes to thin film deposition.Aim. The paper describes results of optimization and fabrication of heterojunction silicon solar cells using the AK-1000 inline tool, adapted for processing of 6-inch wafers.Materials and methods. In the manufacturing of solar cells, crystalline silicon wafers were subjected to wet chemical processes, and then electron, hole, and intrinsic types of conductivity of the layers based on amorphous silicon were deposited by plasma-chemical deposition. Precipitation of oxide transparent conductive layers was carried out by magnetron sputtering. To optimize the processes of obtaining solar cells, measurements of the reflection coefficient, of lifetime of minority carriers, and of current – voltage characteristics were used.Results. As a result of the work, heterojunction solar cells were obtained in a laboratory in Kazakhstan with an efficiency of 20% without using of traditional diffusion processes for solar cells manufacturing.Conclusions. The output parameters associated with light conversion efficiency demonstrate the possibility of further optimization of the parameters affecting the performance of heterojunction solar cells.Introduction. Heterojunction silicon solar cells represent one of the most promising directions for the development of solar photovoltaics. This is due to both their high power conversion efficiency and reasonable likelihood for further growth in performance, as well as good commercial potential of this technology, which relies on a transition from conventional diffusion-based processes to thin film deposition.Aim. The paper describes results of optimization and fabrication of heterojunction silicon solar cells using the AK-1000 inline tool, adapted for processing of 6-inch wafers.Materials and methods. In the manufacturing of solar cells, crystalline silicon wafers were subjected to wet chemical processes, and then electron, hole, and intrinsic types of conductivity of the layers based on amorphous silicon were deposited by plasma-chemical deposition. Precipitation of oxide transparent conductive layers was carried out by magnetron sputtering. To optimize the processes of obtaining solar cells, measurements of the reflection coefficient, of lifetime of minority carriers, and of current – voltage characteristics were used.Results. As a result of the work, heterojunction solar cells were obtained in a laboratory in Kazakhstan with an efficiency of 20% without using of traditional diffusion processes for solar cells manufacturing.Conclusions. The output parameters associated with light conversion efficiency demonstrate the possibility of further optimization of the parameters affecting the performance of heterojunction solar cells

Structure, impurity composition, and photoluminescence of mechanically polished layers of single-crystal silicon

The introduction of optically active defects (such as atomic clusters, dislocations, precipitates) into a silicon single crystal using irradiation, plastic deformation, or heat treatment has been considered a possible approach to the design of silicon-based light-emitting structures in the near infrared region. Defects were introduced into silicon plates by traditional mechanical polishing. The changes in the defect structure and the impurity composition of damaged silicon layers during thermal annealing (TA) of a crystal were examined using transmission electronic microscopy and x-ray fluorescence. Optical properties of the defects were studied at 77 K using photoluminescence (PL) in the near infrared region. It has been shown that the defects generated by mechanical polishing transform into dislocations and dislocation loops and that SiO2 precipitates also form as a result of annealing at temperatures of 850 to 1000°C. Depending on the annealing temperature, either oxide precipitates or dislocations decorated by copper atoms, which are gettered from the crystal bulk, make the predominant contribution to PL spectra. © 2005 Pleiades Publishing, Inc