Integrated glove box system for optoelectronic thin films

• Subject Area: Materials Engineering ; Electrical Engineering and Information Technology
• Term: Funded in 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 465013551

Many materials are sensitive to the oxygen or water molecules in the atmosphere and therefore cannot be reliably synthesized or characterized in air. Therefore, in this application an integrated glovebox array is presented in which (atmosphere-sensitive) organic and organic-inorganic compounds can be produced and characterized autonomously in an inert atmosphere. Organic-inorganic perovskite materials in particular play a major role here, as they cover a large bandgap range and can thus be used in a tandem approach with silicon, but also have the potential to be used in optoelectronics, e.g. for lasers, light-emitting diodes, quantum sensors or sensitive detectors in the medical field. Crucially, perovskites are also direct semiconductors, which means they can be deposited on flexible substrates. This opens up new possibilities, e.g. flexible solar cells on curved surfaces such as building facades or car roofs. Four interconnected glove boxes are planned for this purpose. In the first glove box, thermal evaporation of perovskite layers and metals is conducted, which is relevant e.g. for perovskite/silicon tandem solar cells. In addition, this glove box also contains an atomic layer deposition (ALD) setup, which is used to conformally deposit metal oxides, e.g., TiO2 or SnO2, onto textured Si solar cells. In particular, the ALD system is also requieed for transparent top electrodes on perovskites, which are the basis for a perovskite-silicon tandem, since the metallic electrodes prevent light from passing through the perovskite layer to the silicon sub-cell. The ALD system can also be operated at low temperatures, which allows the investigation of particularly temperature-sensitive processes, as well as organic interlayers. The ALD system is also suitable for perovskite single-junction solar cells. In addition, ITO (fluorine-doped SnO2) deposition is possible in the metal evaporation chamber to ensure a conductive transparent termination layer, which is essential for tandem solar cells.The second glove box is used to prepare the various perovskites, hole conductor layers, etc. These are then later either evaporated (glove box 1) or applied from wet-chemistry methods (glove box 3). The third glove box is used for wet chemical processes, such as applying thin perovskite layers from a liquid precursor. This allows the fabrication of optoelectronic perovskite devices like single-junction solar cells, light-emitting diodes or sensors on flexible substrates. The fourth glove box is used to characterize the optoelectronic devices (e.g., the current-voltage characteristic of a solar cell). The system is such that the entire process can take place under controlled conditions.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Integriertes Handschuhkastensystem für optoelektronische Dünnschicht-Filme
• Instrumentation Group: 0930 Spezialgeräte der Halbleiterprozeßtechnik
• Applicant Institution: Universität Stuttgart
• Leader: Professor Dr. Michael Saliba