A. Drygała

Silicon solar cells with Al2O3 antireflection coating

The paper presents the possibility of using Al2O3 antireflection coatings deposited by atomic layer deposition ALD. The ALD method is based on alternate pulsing of the precursor gases and vapors onto the substrate surface and then chemisorption or surface reaction of the precursors. The reactor is purged with an inert gas between the precursor pulses. The Al2O3 thin film in structure of the finished solar cells can play the role of both antireflection and passivation layer which will simplify the process. For this research 50×50 mm monocrystalline silicon solar cells with one bus bar have been used. The metallic contacts were prepared by screen printing method and Al2O3 antireflection coating by ALD method. Results and their analysis allow to conclude that the Al2O3 antireflection coating deposited by ALD has a significant impact on the optoelectronic properties of the silicon solar cell. For about 80 nm of Al2O3 the best results were obtained in the wavelength range of 400 to 800 nm reducing the reflection to less than 1%. The difference in the solar cells efficiency between with and without antireflection coating was 5.28%. The LBIC scan measurements may indicate a positive influence of the thin film Al2O3 on the bulk passivation of the silicon.

Influence of Laser Processing on Polycrystalline Silicon Surface

This paper presents technology of multicrystalline silicon solar cells with laser texturisation step. The texturing of polycrystalline silicon surface using Nd:YAG laser makes it possible to increase absorption of the incident solar radiation. Moreover, the additional technological operation consisting in etching in 20 % KOH solution at temperature of 80°C was introduced into technology of the photovoltaic cells manufactured from laser textured wafers allows to remove laser induced defects but cause the texture to flatten out reducing it optical effectiveness. This paper demonstrates, that laser processing is very promising technique for texturing multicrystaline silicon independent on grains crystallographic orientation compared to conventional texturing methods in technology of solar cells.

Structures, properties and development trends of laser-surface-treated hot-work steels, light metal alloys and polycrystalline silicon

Several examples have been chosen for presentation from a broad array of laser surface treatment technologies currently researched into and used in industry and the examples are distinguished by their extensive possibilities of future and current applications, especially in the tooling, automotive, and power industry. A newly developed methodology has been employed in order to make an objectivized assessment of the relevant laser surface treatment technologies. Contextual matrices and roadmaps and technology information sheets allowing for the mainly qualitative comparisons of the individual technologies according to harmonized criteria were created as a result of employing the methodology.

Characterisation of graphene-based layers for dye-sensitised solar cells application

The influence of the graphene-based counter electrode on the structure, optical properties and electrocatalytic activity of dye-sensitised solar cells (DSCC) was analysed. The graphene and reduced graphene oxide were deposited by CVD and spin-coating method on the FTO glass substrate, respectively. HRTEM investigation confirms the crystallographic structure of graphene. The investigated layers show flat transmittance spectra across the visible and near-infrared region. The charge transfer resistance of the graphene-based film was analysed by electrochemical impedance measurement. The obtained results show the possibility of replacing expensive platinum in DSCC by using graphene-based counter electrode.