The considerable growth of the PV market that started 30 years ago, will lead to a fast growing number end of life modules. If good solutions for recycling are developed, a huge accumulation of this end of life and rejected PV modules can be avoided. The aim of this work was to develop and to evaluate different recycling processes. Finally two methods have given acceptable results namely the pyrolysis in a conveyer belt furnace and the pyrolysis in a fluidised bed reactor. Especially for the fluidised bed reactor process, the development has reached an industrial level with the set-up of a big pilot reactor. The cost effectiveness of the process is demonstrated by the high mechanical yield of the process and the high quality of the reclaimed wafers, as proven by a high cell efficiency after reprocessing. The ecological impact of recycling is very high and the energy pay back time decreases drastically due to the avoided high energy consumption of the reclaimed silicon wafer.

The objective of this work is to improve the acceptability of building integrated renewable energy conversion by developing high performance photovoltaic building elements with a high visual appeal. After an exercise of translating the visual appeal into technical specifications, a number of novelties are introduced both on the level of the crystalline silicon solar cell structure, the required production equipment and for the module manufacturing. Supporting the development of the new products with both reliability testing and an extended outdoor performance evaluation, a number of highly efficient demonstrator building elements have been manufactured.

This paper describes an integrated approach towards the realisation of modules based on rear contacted solar cells joining experiences in cell and module manufacturing. While research is ongoing on novel interconnection schemes, from an analysis of different possibilities, a methodology was selected that allows the introduction of the interconnection approach within a production line with minor investments. To support the suggested methodology a number of structural changes were required in the Metallisation Wrap Through cells. However, as these were limited to the layout of the contact pattern, no changes to the established cell process were needed except for the introduction of new screens. Based on the developed simple planar interconnection technology, a number of modules was manufactured with large area (100cm2) multi-crystalline rear contacted solar cells demonstrating the electrical added value of rear contacted solar cells and attaining power densities of over 145 W/m2.

Recently, a lot of progress has been made in the pilot-production of mono- and multicrystalline silicon solar cells by the screenprinting technology. For example, a process based on screenprinting combined with oxide passivation and a plasma-nitride ARC yields cell efficiencies approaching 17% on 100 cm2 CzSi Material. These results ask for a detailed comparison concerning the relative performance of state-of-the-art screenprinted cells compared to the state-of-the-art buried contact structure. This is done by means of 213-simulations using the simulation program SIMUL. It comes out that the efficiency difference between a buried contact technology and a screenprinting technology, both with selective emitter and good surface passivation, is only 0.5% absolute. The efficiency difference between screenprinted cells with a homogeneous emitter and buried contact cells with a selective emitter turns out to be between 1 and 1.5% absolute, depending on the surface passivation quality. Looking at the above-mentioned difference in efficiency, only detailed cost calculations for an industrial production scenario can reveal which process leads to the lowest cost per Wp.

A lot of progress has been made in the pilot-production of mono- and multicrystalline silicon solar cells by the screenprinting technology. For example, a screenprinting process using new metal pastes, fine linewidth printing, the incorporation of surface passivation, Al gettering, BSF and a selective emitter structure yields efficiencies over 17% on 100 cm/sup 2/ Cz-Si material. These results ask for a detailed comparison concerning the relative performance of state-of-the-art screenprinted cells compared to the state-of-the-art buried contact structure. This is done by means of 2D-simulations using the simulation program SIMUL. The efficiency difference between a buried contact technology and a screenprinting technology, both with selective emitter and good surface passivation, is only 0.5-0.6% absolute. The efficiency difference between screenprinted cells with a homogeneous emitter and buried contact cells with a selective emitter turns out to be 1% absolute, provided a good surface passivation is applied. Looking at the above-mentioned difference in efficiency, only detailed cost calculations for an industrial production scenario can reveal which process leads to the lowest cost per Wp.

Recently, a lot of progress has been made in the pilot-production of mono- and multicrystaliine silicon solar cells by the screenprinting technology. For example, a screenprinting process using new metal pastes, fine linewidth printing, the incorporation of surface passivation, AI gettering, BSF and a selective emitter structure yields efficiencies over 17 o/o on 100 cm2 Cz-Si material. These results ask for a detailed comparison concerning the relative performance of State-of-the-art screenprinted cells compared to the state-of-the-art buried contact structure. This is done by means of 2Dsimulations using the simulation program SIMUL. It comes out that the efficiency difference between a buried contact technology and a screenprinting technology, both with selective emitter and good surface passivation, is only 0.5-0.6% absolute. The efficiency difference between screenprinted cells with a homogeneous emitter and buried contact cells with a selective emitter turns out to be 1% absolute, provided a good surface passivation is applied. Looking at the above-mentioned difference in efficiency, only detailed cost calculations for an industrial production scenario can reveal which process leads to the lowest cost per Wp.

AbstractThe penetration of metallic B, Ti, Fe, Cu and Ag in silicon solar cells was studied. They were prepared using the screen printing process for metallization. The level and depth of penetration were determined using secondary ion mass spectrometry (SIMS). Quantitative SIMS depth profile analysis was performed using ion implanted substrates as standard materials. The influence of different production parameters, such as silicon crystal orientation, metallization temperature, composition of the Ag‐paste and the presence of an anti‐reflective TiOx coating on the silicon cells were determined. The penetration of some metallic species has considerable influence on the solar cell characteristics and its efficiency. The penetration levels can not be explained by diffusion but are probably related to more reactive interactions.

The use of an integral printing technique for the fabrication of silicon solar cells is attractive due to its throughput rate, materials utilization, and modular, automatable design. The transfer of this technology from single crystal to semicrystalline silicon requires a significant amount of process optimization. Processing parameters found to be critical include the optimum glass frit content in the silver-based inks, the silver ink firing temperature, and the formation of the back-surface field using screen-printed aluminum layers. Open-circuit voltages as high as 617 mV have been achieved using a novel BSF approach on 4-in wafers. Important mechanisms controlling ink contact resistance, ink sheet resistivity, and ohmic contact on and silicon materials are discussed in this paper. The solar cell stability is a function of the glass frit and the firing temperature of the silver-based inks. Finally, a simple economic analysis, based on the IPEG technique, indicates that screen printing is a cost-effective option when the cell manufacturing is done on a large scale.

The integral screen printing process for the fabrication of silicon solar cells offers a low-cost, continuous technique. Printing has been used for the deposition of active layers, antireflection coatings, front and back metallizations and a back surface field. Processing parameters such as initial surface etching, pre-gettering, types of phosphorous diffusion and back surface field formation are discussed in this paper. A comparison is made between three potentially low-cost silicon materials using the integral screen printing process. These materials include Wacker Silso, HEM polycrystalline silicon, and highly dislocated single crystal silcon.

This paper presents a screen printing process for the metallization of silicon solar cells. The physics and construction of a classical solar cell are reviewed. The results obtained with a screen printing process are comparable with other, more expensive technologies. This technology does not introduce an additional contact resistance on silicon. The process optimization and the influence of different parameters are discussed.