flex!PV_2.0 - Technologies for expanding the functionality and performance of flexible kesterite- and perovskite-based PV

Photovoltaic is still one of the most attractive technologies for a resource-saving and costeffective energy production. The recent developments in the thin film photovoltaic sector show an ongoing positive trend, led by the emerging hybrid perovskite and kesterite absorber technologies. Benefits such as flexibility and semi-transparency as well as the use of low temperature processes allow cost-effective manufacturing processes and hence competitiveness compared to conventional silicon solar cells. Nevertheless, a main focus of both the R&D and the industry is a further development of existing processes and materials from the laboratory towards an industrial mass production. In addition, research has to be constantly adapted to the new materials and technologies, which provide impetus and create new market opportunities in the PV sector. flex!PV_2.0 strives to strengthen the permanence of Austria as a technology location by bundling up the know-how in the fields of material development, coating technologies, device structure and module design, suitable for the kesterite and perovskite absorber. Following innovative concepts and activities are proposed: (i) The synthesis of perovskite monocrystals, through chemical routes and their integration to crystalsol’s membrane cell technology, in order to explore the possibilities of efficiency enhancement. This unconventional perovskite cell construction will permit the decoupling of the perovskite absorber formation from the other cell components and will therefore enhance process flexibility. (ii) The construction of a thin-film perovskite cell, employing material components (inorganic and organic) and cell-design concepts from the well-established OPV area. In this way, core expertise of the project partners in OPV will be fully exploited and valuable results from the previous flex!pv.at project will be further developed. Apart from the perovskite absorber itself, project results will comprise material components including transparent electrodes, electron and hole transport layers, as well as interfacial layers for perovskite passivation, defect reduction and energy band alignment. (iii) The development of a semitransparent and efficient monograin-membrane cell based on the kesterite absorber, through the implementation of newly-developed, transparent back contacts and Cd-free buffers with an optimized energy band structure. The development of semitransparent cells will open new market possibilities for crystalsol’s technology, especially in the BIPV area. (iv) Focusing on high-throughput, solution-based routes will be scaled up from cell level production to sheet-to-sheet or roll-to-roll module processing. The scaling-up strategies will address the issues of efficiency decrease in modules, caused by factors such as layer thickness inhomogeneity and module interconnection losses. For these issues the consortium will build upon concepts and know-how acquired in the framework of the previous flex!pv.at project. (v) The project will also focus on the materials, cell and module stability, which is a critical issue especially for the hybrid perovskite absorbers, still preventing their commercialization. A wide range of characterization techniques and various testing conditions of light, humidity and temperature will be employed, in an attempt to unveil the intrinsic limitations and potential of these promising absorber technologies.