LAFLEX2T

Flexible Large area 2T monolithic Tandem PSC-CIGS

Publieke samenvatting / Public summary

Aanleiding
Cost-effective multi-junction (MJ) device architectures are a promising approach to increase the Power Conversion Efficiency (PCE) of the solar cells/module/panel in order to lower the levelized cost of energy (LCOE). This will decrease the price of an installed photovoltaic (PV) system, which is nowadays mostly determined by the non-module (balance of system) and installation costs, instead of the PV module manufacturing cost (see Fig. 1.1A appendix). Recently, the PV community is investigating tandem hybrid architectures, combining a top cell based on a metal halide perovskite absorber (PSC) with a commercial bottom PV device such as crystalline silicon (c-Si) or copper indium gallium selenide (CIGS). The advantage of a monolithic tandem PSC-CIGS architecture is its compatibility with lightweight flexible plastic or metal foils by means of roll to roll (R2R) manufacturing, which can further reduce the manufacturing and the installation costs, as well as the environmental footprint of the KhW generated.

Doelstelling
The main target of this project is to design and engineer the first highly efficient flexible two-terminal (2T) thin-film solar devices based on hybrid tandem architectures with CIGS bottom cell and PSC top cell configuration, and on a relevant device size (>80 cm2) to demonstrate industrial feasibility. CIGS will be the industrial platform on which the perovskite top cell will be developed as additional building block to boost the device conversion efficiency. In order to achieve this target, this project will bring together academic partners and research institutes (TU/e, TUD, TNO, and UH), Dutch companies (STS, and Nouryon) and frontrunner end-user (MiaSolé). The “LAFLEX2T” know-how and infrastructures present in the consortium will be used to i) develop up-scalabling compatible R2R perovskite ink and functional layers for a stable top cell; ii) tune the stoichiometry of the CIGS absorber and thus the bandgap in order to maximize the complementary absorption of to the two sub-cells, iii) to select and synthetize charge transport layers to build up an efficient recombination junction layer which will provide the monolithic series connection between the two sub-devices.

Korte omschrijving
TNO and STS will focus on the development of R2R compatible solution-processing approaches for the synthesis of metal halide perovskite absorbers on large area with a bandgap of 1.6eV. MiaSolé flexible CIGS will be used as starting material to develop the 2T architecture in this project. At the same time, due to the R&D facilities available in TNO and UH for the CIGS fabrication complimentary to the MiaSolé industrial production manufacturing line, TNO and UH will engineer the CGIS bandgap towards 1.0eV from the current 1.2eV (see Fig. 1.2A). Given the relevance of atomic layer deposited (ALD) metal oxide charge transport layers and suitability with industrial production because of the development of spatial-ALD (s-ALD), TNO, TU/e and Nouryon will investigate the most suitable ALD metal precursors to develop and up-scale processes for charge transport layers, which will be integrated in the above- mentioned device structure as components of the tunneling junction. Optical and electrical modeling will be carried out by TU Delft in order to optimize the device performance and to provide the input required in the device design and materials processing.

Resultaat
The “LAFLEX2T” will deliver the first large area, highly efficient monolithic 2 terminal flexible tandem perovskite-CIGS cell on at least 80 cm2 (active area). This large area tandem device will have an efficiency of at least 19%, potentially approaching 20%, with an efficiency gain of at least 1.5% compared to the power conversion efficiency of the single flexible CIGS device used as initial platform.
The project represents a great opportunity for Dutch equipment manufacturers (Smit Thermal Solutions), and materials companies (Nouryon) to position themselves in this PV market. The project also enables TNO to create new know-how together with the University partners, enabling a fast future transfer from lab to fab scale. Therefore, this project fulfils the ambition of TKI UE to support the Dutch economy and the development of novel concepts/prototype toward high efficiency PV devices based on up-scaled thin-flm PV technologies, usable in future from other Dutch materials manufacturers as well as construction companies aiming for BIPV, VIPV products.