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8th World Conference on Photovoltaic Energy Conversion; 1099-1104, In this work we give an overview of the module monitoring results achieved within the H2020 funded project called HighLite. A dedicated online monitoring platform has been developed for the project to group and treat the data from all partners with homogeneous procedures. Monitoring of advanced prototype modules developed in the project and based on various cells and interconnection approaches, like silicon-heterojunction (SHJ)-shingle, TopCon-shingle, cut interdigital back-contact cells (cut-IBC) are reported. We describe key learnings from monitoring modules for various applications including building-applied PV (BAPV) and building-integrated PV (BIPV). Annual energy yield up to 1900 kWh/kWp is expected in Cadarache (France) based on HighLite PV technology. Temperature corrected performance ratios are used for a ranking of the new technologies against the reference PERC modules.

38th European Photovoltaic Solar Energy Conference and Exhibition; 533-537, The EU crystalline silicon (c-Si) PV manufacturing industry has faced strong foreign competition in the last decade. To strive in this competitive environment, the EU c-Si PV manufacturing industry needs to focus on highly performing c-Si PV technologies and on reducing environmental impact (lower CO2 footprint, improved sustainability, recyclability, etc.). In this work, we give an overview of the latest results achieved within the H2020 funded project called HighLite which addresses the work programme LC-SC3-RES-15-2019: Increase the competitiveness of the EU PV manufacturing industry. We report the progress made when implementing novel layers and processes in existing pilot-lines producing high-efficiency n-type silicon heterojunction (SHJ) cells with a shingle layout and interdigitated back-contact (IBC) cells with passivated contacts. In particular, we present the work done together with several industrial partners towards innovative production equipment for assembly of cut-cells into PV modules. Finally, we explain key learnings made so far when tailoring c-Si PV modules for various applications including building-applied PV (BAPV), building-integrated PV (BIPV) and vehicle-integrated PV (VIPV).

37th European Photovoltaic Solar Energy Conference and Exhibition; 312-316, In this work the construction and characterization of a new device for the accurate measurement of busbarless, bifacial solar cells is presented. The measuring apparatus was designed and built according to the principle of the N.I.C.E.™ (New Industrial Cells Encapsulation) technology. For reasons of comparability, the measurement setup was based as closely as possible on the setup of manufactured N.I.C.E.™ mini modules. This equipment is used to determine the series resistance as a function of the vacuum and the temperature prevailing in the module. The results obtained are then compared with the results of manufactured solar modules in order to assess how well the test setup predicts the performance of the cell in the subsequent module.

29th European Photovoltaic Solar Energy Conference and Exhibition; 1991-1995, The highest conversion efficiencies are reached by multi-junction III-V solar cells. Wafer-bonding offers new possibilities to advance beyond the industrial standard triple-junction cells and its efficiency limitations. Here we present for the first time results of two novel 4-junction device concepts based on direct wafer-bonding with a realistic efficiency potential of 50% under concentrated sunlight. In the first concept, an inverted grown GaInP/GaAs tandem cell is bonded to a metamorphic GaInAs/Ge tandem cell. Frist bonded 4-junction solar cell on Ge shows an efficiency of 34.5% under one sun AM1.5d. In the latter concept a GaSb cell will be bonded to an inverted metamorphic triple-junction solar cell. The main challenge in this approach is a conductive direct wafer bond between the two cell stacks. Here, bond characteristics between GaSb and Ga0.29In0.71P and another between GaSb and Ga0.79In0.21As are shown for the first time.

26th European Photovoltaic Solar Energy Conference and Exhibition; 1089-1093, Most high-efficiency concepts for silicon solar cells utilise passivated surfaces and/or novel metallisation approaches. For these devices an anneal step, preferential in forming gas ambient, is beneficial or even crucial. Annealing is known to activate or improve surface passivation, facilitate metal-silicide formation, improve adhesion of metal contacts and cure potential crystal damage. Challenges for industrial solutions of anneal processes are a precise control of the process atmosphere and temperature, as well as a high throughput and easy integration into production lines. We present a high capacity inline annealing system that addresses these tasks with a throughput of over 1000 wafers per hour. The gas locks, located at the entrance and exit of the furnace, allow for an effective separation of laboratory and forming gas process ambient, which results in a residual oxygen concentration of a few ppm. Inline annealed silicon solar cells with a thermal oxide passivated rear surface show the same conversion efficiency as reference cells, which are annealed in a single wafer reactor. The specific cost of inline annealing in forming gas is calculated to be below 1.1 €ct/Wp.

25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 1908-1911, This works presents the first results of the investigation of the minority carrier lifetime reduction during industrial sputtering of metal seed layers for front side metallization of crystalline silicon solar cells with respect to the cathode performance and the exposure time. Furthermore a method to avoid the reduction of the effective lifetime during sputtering is demonstrated as well as the determination of the ion energy input with the retarding field analysis. All investigations were done by using a new pilot system for inline sputtering. Because of the deposition from below different concepts for substrate holders were used to minimize shadowing effects. Compared to previous investigations a possibility to avoid the lifetime reduction was determined. This underlines the possibility of sputtering for front side metallization.

Silicon solar cells that feature screen printed front contacts and a passivated rear surface with local contacts allow higher efficiencies compared to present industrial solar cells that exhibit a full area rear side metallization. If thermal oxidation is used for the rear surface passivation, the final annealing step in the processing sequence is crucial. On the one hand, this post-metallization annealing (PMA) step is required for decreasing the surface recombination velocity (SRV) at the aluminum-coated oxide-passivated rear surface. On the other hand, PMA can negatively affect the screen printed front side metallization leading to a lower fill factor. This work separately analyzes the impact of PMA on both, the screen printed front metallization and the oxide-passivated rear surface. Measuring dark and illuminated IV-curves of standard industrial aluminum back surface field (Al-BSF) silicon solar cells reveals the impact of PMA on the front metallization, while meas uring the effective minority carrier lifetime of symmetric lifetime samples provides information about the rear side SRV. One-dimensional simulations are used for predicting the cell performance according to the contributions from both, the front metallization and the rear oxide-passivation for different PMA temperatures and durations. The simulation also includes recombination at the local rear contacts. An optimized PMA process is presented according to the simulations and is experimentally verified. The optimized process is applied to silicon solar cells with a screen printed front side metallization and an oxide-passivated rear surface. Efficiencies up to 18.1% are achieved on 148.8 cm2 Czochralski (Cz) silicon wafers.

24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 1479-1482, In this paper first results on the stability and applicability for an inline sputtering pilot system (Applied Materials ATON 500 Ev + Sp) with industrially feasible deposition rates are shown. The system consists of two different process chambers, one for thermal evaporation and a second one for sputter deposition of two different metals. The applicability of the sputtering process for the front side metallization has first been determined in an experimental setup on a non PV dedicated system. Different experiments were performed to evaluate the properties of the sputtered layers. To determine the possible damage of the passivation layer during the sputter deposition, test structures for minority carrier lifetime measurements were prepared. The layer growth of the sputtered metal depends on the temperature of the substrate and the sputtered target material properties as well. To determine the layer growth and the homogeneity, experiments were performed to evaluate the sheet resistance and to identify their relation to an industrial inline metallization process with various deposition rates after transferring the process to the pilot system. Sheet resistance measurements are additionally used to analyze a very important aspect of the metallization process, the silicide formation. Depending on the applied metal for the deposited layer, the time and temperature of the tempering process has to be chosen individually in order to from a suitable silicide layer for subsequent contact formation.