Sun is the most powerful energy source available on the Earth, it can be utilized via solar cells (SC), used for the conversion of solar energy into electric power. This way global energy demand could be fully satisfied with properly improved SCs. Within last five years hybrid solid-state solar cell technology, particularly one based on perovskite light absorber, became the object of great interest for creation of new generation of photovoltaic devices. These perovskite solar cells (PSC) are known for simplicity of their construction, low cost of materials needed and high efficiency (at present exceeding 23%). Currently dozens of known companies intensely work in the field of PSC constructing and optimizing photovoltaic devices. Known semiconductors are tested; new ones are created and patented, as the need for materials that would improve efficiency of the devices and allow simplification of production rapidly grows every year. Although perovskite solar cells had reached impressive efficiencies within the last five years (from 3.8% up to 23.2%), there are still several obstacles for their commercialization. During the course of the project charge transporting molecules, capable of forming self-assembled monolayers (SAM), will be synthesized. SAM formation will be investigated in the p-i-n structured PSCs on both the transparent conductive electrode and on the surface of the perovskite.
Project funding:
Projects funded by the Research Council of Lithuania (RCL), Projects carried out by researchers’ teams
Project results:
During the project new simple charge transporting materials that form SAM were synthesized and integrated into perovskite solar cells. The coating process has been developed so that new SAMs can be deposited on transparent conductive oxides via spin-coating or by dipping the substrate into the solution, both yielding layers of comparable properties, high reproducibility and ease of fabrication. The SAM materials were applied in the production of a functioning solar cell in collaboration with Helmholtz Zentrum Berlin (HZB) in Germany. These SAMs outperform polymer PTAA, material that enabled the highest performing p–i–n PSCs to date, in efficiency, stability and versatility. Integrating a SAM contact into a monolithic CIGSe/perovskite and c-Si/perovskite tandem solar cells, led to record breaking certified efficiency of 24.16% and 29.15% respectively, surpassing the previous records of 22.4% and 28% accordingly. Importantly, demonstrated solar cells are fabricated without additional passivation layers, additives or dopants.
The results of the research have been reported in four publications in the highly rated journals Energy Environ. Sci. (Q1, IF=30.2), Adv. Energy Mater. (Q1, IF=25.2), Adv. Funct. Mater. (Q1, IF=18.81), Science (Q1, IF=47.73). Very good results obtained during the project allowed to start the patenting process, German patent (DE102019116851B3), WIPO patent application (WO2020254665A1). The compounds obtained during the research were successfully commercialized in Europe by the Swedish company Dyenamo AB and in Japan by the company Tokyo Chemical Industry Co., Ltd. This work is attributed to TRL 9 technology readiness level.
Period of project implementation: 2019-05-20 - 2022-06-30
Project coordinator: Kaunas University of Technology
