The Li Insertion/Extraction Characteristics of Amorphous Silicon Thin Films

Amorphous hydrogenated silicon (a-Si:H) is known to be a perspective material for negative electrodes of modern lithium-ion batteries. The electrochemical lithium insertion into thin-film a-Si:H electrodes is studied using chronopotentiometry, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The electrodes were grown on stainless-steel substrates by glow discharge at the temperature of T = 100 and 250 oC. The insertion capacity of the films deposited at 250 oC is higher than that of the equally thick films deposited at 100 oC. The increase in the film thickness involves the drastic decrease of the insertion capacity during the potential cycling. An equivalent circuit is suggested for the lithium insertion to the electrodes, which comprises electrolyte resistance and three RC-chains in series, each chain being a parallel connection of a resistance and a constant-phase element, which relate to charge transfer at the silicon/electrolyte interface, charge transport in the passive film on silicon, and the lithium diffusion into the silicon bulk. With the potential cycling in progress, the most significant changes are observed in the chain relating to the passive film. The Li diffusion coefficient in a-Si:H is estimated from data of CV and EIS. It equals D = 4 ·10–13 and 10–13 cm2 s–1 for electrodes synthesized at a temperature of 100 and 250 oC, respectively

Temperature Dependence of Resistivity and Current-Voltage Characteristics of the Films of Composites Based on Modified Carbon Multiwalled Nanotubes and Graphite

A film composites based on modified multiwalled carbon tubes and polymer (95/5 wt. %) Respectively on paper, without the paper by directional spinning from the liquid phase and graphite. The temperature dependence of the resistivity () in the range T 77-410 K and the corresponding current-voltage charac-teristics. Detected irreversible transitions from semiconducting to metallic conductivity in carbon nono-trubkah and a maximum at T 340 K. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3516

The Li Insertion/Extraction Characteristics of Amorphous Silicon Thin Films

Amorphous hydrogenated silicon (a-Si:H) is known to be a perspective material for negative electrodes of modern lithium-ion batteries. The electrochemical lithium insertion into thin-film a-Si:H electrodes is studied using chronopotentiometry, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The electrodes were grown on stainless-steel substrates by glow discharge at the temperature of T = 100 and 250 oC. The insertion capacity of the films deposited at 250 oC is higher than that of the equally thick films deposited at 100 oC. The increase in the film thickness involves the drastic decrease of the insertion capacity during the potential cycling. An equivalent circuit is suggested for the lithium insertion to the electrodes, which comprises electrolyte resistance and three RC-chains in series, each chain being a parallel connection of a resistance and a constant-phase element, which relate to charge transfer at the silicon/electrolyte interface, charge transport in the passive film on silicon, and the lithium diffusion into the silicon bulk. With the potential cycling in progress, the most significant changes are observed in the chain relating to the passive film. The Li diffusion coefficient in a-Si:H is estimated from data of CV and EIS. It equals D = 4 ·10–13 and 10–13 cm2 s–1 for electrodes synthesized at a temperature of 100 and 250 oC, respectively

Efficiency a-Si:H solar cell. Detailed theory

We develop a detailed formalism to photoconversion efficiency η of hydrogenated amorphous silicon ( a-Si:H ) based solar cells with a contact grid. This efficient three-dimensional model allows firstly optimization of the p i n sandwich in terms of carrier mobilities, thickness of the layers, doping levels and others. Secondly, geometry of the grid fingers that conduct the photocurrent to the bus bars and ITO/SiO₂ layers has been optimized, and the effect of non-zero sun beam incidence angles has been included as well. The model allows optimization of the amorphous Si based solar cells in a wide range of key parameters

Characterization of a-Si:H/c-Si interface by admittance spectroscopy

International audienc

Characterization of a-Si:H/c-Si interface by admittance spectroscopy

International audienc

Photoconductivity of two-phase hydrogenated silicon films

LGEP 2010 ID = 592International audienc

Photoconductivity of two-phase hydrogenated silicon films

LGEP 2010 ID = 592International audienc