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The purpose of this study was the comparison and analysis of the electrical parameters of two kinds of silicon solar cells (mono- and multicrystalline) of different emitter resistance.

By controlling of diffusion parameters, silicon mono- (Cz-Si) and multicrystalline (mc-Si) solar cells with different emitter resistance values were produced – 22 and 48 Ω/□. On the basis of current-voltage measurements of cells and contact resistance mapping, the properties of final solar cells based on two different materials were compared. Additionally, the influence of temperature on PV cells efficiency and open circuit voltage (U_oc) were investigated. The PC1D simulation was useful to determine spectral dependence of external quantum efficiency of solar cells with different emitter resistance. The silicon solar cells of 25 cm² area and 240 µm thickness were investigated.

Considering the all stages of cell technology, the best structure is silicon solar cell with sheet resistance (R_sheet) of 45-48 Ω/□. Producing of an emitter with this resistance allowed to obtain cells with a fill factor between 0.725 and 0.758, U_oc between 585 and 612 mV, short circuit current (I_sc) between 724 and 820 mA.

Measurements and analysis confirmed that mono- and multicrystalline silicon solar cells with 48 Ω/□ emitter resistance have better parameters than cells with R_sheet of 22 Ω/□. The contact resistance is the highest for mc-Si with R_sheet of 48 Ω/□ and reaches the value 3.8 Ωcm.

In this paper, we aim to investigate the influence of the hydrogenated silicon nitride layers deposited by a large area 13.56 MHz plasma-enhanced chemical vapour deposition system on the electrical activity of the surface and interfaces of the grains for solar cells fabricated on microcrystalline silicon and multicrystalline silicon.

The characterization of current-voltage parameters of 25 cm² solar cells manufactured with different passivation and antireflective layers are presented. After spectral response measurements, external quantum efficiency was calculated, and the final results are shown graphically. The passivation effect concerning grain areas was evaluated more precisely by light-beam-induced current scan maps (LBIC).

The final impact of the type of passivation layer on surface and grain boundary photoconvertion in solar cells is determined.

The passivation effect concerning grain areas was evaluated more precisely by LBIC.

The purpose of this paper was the investigation of transparent conducting oxide (TCO) applied as an additional part of front metal electrode of crystalline silicon solar cell. Transparent conducting oxides are widely used as counter electrodes in a wide range of electronics and optoelectronics applications, e.g. flat panel displays. The most important optical and electrical requirements for TCOs are high optical transmittance and low resistivity. This low resistivity might invoke the possibility of increasing the distance between the fingers in the solar cell front electrode, thus decreasing the total area covered by metal and decreasing the shadowing loss.

In the present work, thin films of indium-tin-oxide (ITO) as a transparent counter electrodes, were evaporated on the surface of silicon n+-p junction structures used in solar cells. The influence of the properties of ITO electrode on the electrical performance of prepared solar cells was investigated through optical and electrical measurements. The discussion on the influence of deposition conditions of the TCO films on recombination of the photogenerated electrical charge carriers and solar cell series resistance was also included.

In this work, the fingers lines 100 μm width were screen-printed on the c-Si wafer with ITO layer. Monocrystalline silicon 25 cm 2,200-μm-thick wafers, were used for this testing. The usefulness of the ITO films as antireflection coating was discussed as well. It is commonly known that electrical performance of solar cells is limited by surface passivation. Despite this, the obtained results for ITO-Si structures showed relatively high value of short circuit current density (Jsc) up to 33 mA/cm2.

Our experiments confirmed the potential of application of ITO as anti-reflection coating (ARC) layer and according to their low resistivity possible use as a functional counter electrodes in photovoltaic structures.

The paper aims to show application of the electrochemically deposited coatings for thickening of the screen printed electric paths potentially applied in photovoltaic cells.

The electric paths were screen printed with the use of silver-based paste. The paths were thickened by electrodeposition of thin copper layer in potentiostatic regime from surfactant-free plating bath. The morphology and surface quality of the paths were studied by imaging with scanning electron microscopy.

The electric paths can be thickened successfully, but quality for the screen printed substrate determines quality of deposited layer. The EDX analysis confirmed that the deposited copper layer covered uniformly the printed paths.

The adhesion of the copper-covered path to the silicon wafer surface depends on adhesion of the original screen printed path.

This paper confirms that electrodeposited copper can be applied for screen printed silver paths thickening in a controllable way.

The paper aims to present results of investigations carried out on the front electrode of the solar cell. The front-side electrode for solar cells based on crystalline material is obtained by the screen printing method. Screen printing has been the prevailing method of electrode deposition because of its low cost. One of the ways to improve the cell efficiency and reduce the production costs is a further refinement of the metal electrode screen printing process.

The researches were focused on the modification of mechanical parameters of screen printing process to ensure the best possible cross-section of the front electrode geometry. The main printing process parameters were constant, however, the print speed was variable. The obtained fine line of front contact was characterized morphologically – the dimension and geometry of the front contact cross-section – by scanning electron microscopy technique.

The thin paths of 100 μm in width were screen printed applying a new silver-paste made by Du Pont. The printing speed has significant effect on print quality in the way that the lower speed enhanced the printed results.

For newest pastes (e.g. PV17D) influence of screen printing parameters on the front metallic electrodes geometry of solar cell is not so significant. Presented screen printing process can still give good results, but the further optimization for the new paste must be performed to achieve better cross-section geometry.

This paper confirms that one-step screen printing process can still give good results. The screen printed thin paths of 100 μm in width have good cross-section aspect ratio.

The purpose of this study is to verify the possibility of applying alumina (Al₂O₃) as the passivation and antireflective coating in silicon solar cells.

Model of a studied structure contains the following layers: Al₂O₃/n+/n-type Si/p+/Al₂O₃. Optical parameters of the aluminium oxide films on silicon wafers were measured in the range of wavelengths from 250 to 1,400 nm with a spectrophotometer Perkin Elmer Lambda 900. The minority carrier lifetime at the start of the n-type Si base material and after each of the next technological process was analysed by a quasi-steady-state photoconductance technique. The electrical parameters of the solar cells fabricated with four different thickness of the Al₂O₃ layer were determined on the basis of the current-voltage (I-V) characteristics. The silicon solar cells of 25 cm² area and 300 µm thickness were investigated.

The optimum thickness of alumina as passivation layer is 90 nm. However, considering also antireflective properties of the first layer of a photovoltaic cell, the best structure is silicon with alumina passivation layer of 30 nm thickness and with TiO2 antireflective coatings of 60 nm thickness. Such solution has allowed to produce the cells with the fill factor of 0.77 and open circuit voltage of 618 mV.

Measurements confirmed the possibility of applying the Al₂O₃ as a passivation and antireflective coating (obtained by atomic layer deposition method) for improving the efficiency of solar cells.

The purpose of this paper is to investigate the behavior of interconnections between solar cells in a glass-free solar modules. As glass weight can be a limitation, it is still interesting to investigate other types of systems, especially when the glass was replaced with a polymeric front sheet. Such systems can be more sensitive for the solar cell interconnection ribbon fatigue.

To examine this effect, the set of glass-based and glass-free modules were prepared using various ribbon thickness and treatment concerning its stretching or curving before lamination. Furthermore, additional reinforcement of the connection between the ribbon and the solar cell was proposed. The prepared modules were exposed to the cyclic temperature variation in the environment chamber. The number of cycles after which the interconnection maintains its conductivity was noted.

Changing the outer layers into more elastic ones requires additional care for the ribbon treatment because interconnections become more sensitive for a system relative displacement. To secure interconnection before fatigue an additional curving of ribbon between solar cells can be introduced whereas the best results were obtained for a system with aluminum plate laminated as an interlayer.

The paper presents a new system of a glass-free solar module based on epoxy-glass fiber composite as a backsheet. The glass front sheet was replaced with an elastic, transparent polymer. Such construction can be used in a system where the glass weight is a limitation. As glass has a structural function in traditional modules and limits fatigues of interconnections the proposed system requires additional ribbon treatment to preserve long module life-span.

The purpose of this paper is to present results of the studies on modification of ethylene-vinyl acetate (EVA) encapsulation foil to be used as thermal interface material (TIM). It is estimated that poor thermal management in electronic devices can cause over 50 per cent of failures. As the junction temperature rises, the failure rate for electronics increases exponentially. To ensure sufficient heat transfer from its source, TIMs are used in various circuits. On the other hand, it is important to ensure high electric resistivity of the designed TIM.

The focus of the investigation was twofold: modification of EVA with both graphene oxide (GO) and silver nanopowder (nAg); and TIM applicability through lamination of photovoltaic cells with standard and modified EVA foil. The main problem of a new type of encapsulant is proper gas evacuation during the lamination process. For this reason, reference and modified samples were compared taking into account the percentage of gas bubbles in visible volume of laminated TIM. Finally, reference and modified TIM samples were compared using differential scanning calorimetry (DSC) and laser flash analysis (LFA) measurements.

The proper parameters of the lamination process for the modified EVA foil - with both GO and organometallic nAg particles - were selected. The nAg addition results in an increase in thermal conductivity of the proposed compositions with respect to unmodified EVA foil, which was confirmed by DSC and LFA measurements.

The experiments confirmed the potential application of both EVA foil as a matrix for TIM material and nAg with GO as an active agent. Proposed composition can bring additional support to a solar cell or other electronic components through effective heat removal, which increases its performance.

The photovoltaic modules with front glass as a protective layer are the most popular type in the industry, but for some applications it can be considered as too heavy. One of the approaches is to laminate the cells using PMMA [Poly(methyl methacrylate)] as the front layer. This polymer has good mechanical strength and optical properties but exhibits low adhesion to lamination foil. To increase adhesion between these two materials, PMMA surface treatment may be required.

To examine the PMMA treatment influence on the sample, adhesion samples’ surfaces were modified by grinding and laser cutting. Also two types of PMMA available in the market were tested, namely, smooth and satin types. The quality of lamination was determined using two methods, namely, tear test with recorded maximal tear force achieved for the samples, and environment chamber tests, in which the system resistance against the cyclic temperature variation was evaluated.

Additional treatment of the PMMA surface lead to increased adhesion of the lamination foil used. Ethylene-vinyl acetate foil in the PMMA system is sensitive to temperature variation, which can lead to system delamination, whereas polyvinyl butyral foil exhibits better environmental performance and even its adhesion to PMMA is lower.

This paper presents atypical surface modification methods that contributed to higher adhesion of lamination systems in glass-free solar modules. Glass front sheet and polymeric backsheet were replaced with PMMA. As the adhesion mechanism in the PMMA-lamination foil system differs from that in the traditional glass system, different PMMA surface treatments need to be evaluated.

The paper aims to present a research on the impact of the stabilization process of a thin metallic layer (Ni-P) produced on a ceramic surface (Al₂O₃) by means of electroless metallization on its electric parameters and structure. On the basis of the research conducted, the existence of a relationship between resistance (R) and the temperature coefficient of resistance (TCR) of the test structure with a Ni-P alloy-based layer and the temperature of stabilization was proposed.

Metallic Ni-P layers were deposited on sensitized and activated substrates. Metallization was conducted in an aqueous solution containing two primary ingredients: sodium hypophosphite and nickel chloride. The concentration of both ingredients was (50-70) g/dm³. The process lasted 60 min, and the metallization bath pH was kept at 2.1-2.2, whereas the temperature was maintained at 363 K. The thermal stabilization process was conducted in different temperatures between 453 and 623 K. After the technological processes, the resistance and TCR of the test structures were measured with a micro ohmmeter. The composition and the morphology of the resistive layer of the structures examined was also determined.

The dependence of the resistance on the temperature of the stabilization process for the temperature range 553 to 623 K was described using mathematical relationships. The TCR of test resistors at the same thermal stabilization temperature range was also described using a mathematical equation. The measurements show that the resistive layer contains 82.01 at.% of nickel (Ni) and 17.99 at.% of phosphorus (P).

The results associate a surface morphology Ni-P alloy with the resistance and TCR according to temperature stabilization. The paper presents mathematical relationships that have not been described in the literature available.