dry film processing of hybrid perovskites with tailored optoelectronic properties

• Applicant: Professorin Dr. Anna Köhler, since 11/2022
• Subject Area: Synthesis and Properties of Functional Materials
• Term: from 2020 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 434342094

Optoelectronic devices based on hybrid perovskites as active semiconductor have undergone rapid development in recent years. Despite intensive research efforts, however, a highly scalable manufacturing method for hybrid perovskites that offers a high degree of control over layer properties has not yet been established. This is due to the high complexity of the current manufacturing methods, in which material synthesis and layer formation are inseparably linked. Therefore, this project aims to understand how the resulting optoelectronic properties of perovskites can be controlled by the dry process methods developed here. The aim is to understand and control dry processing in order to be able to produce tailor-made materials and films for various possible applications. Such layers are to be realized by processing powders of hybrid perovskites by dry spraying in combination with a subsequent pressure treatment. By processing the powders using the dry spray process, adhesive thin films can be produced, while the pressure treatment ensures surface roughness of only a few nanometers. This process also offers the potential for simple upscaling without the use of solvents and represents a new production route for perovskite films for this material class, which offers increased overall process control compared to existing approaches.On this basis, the structural properties of synthesized perovskite powders are first measured and their electronic structure identified. In order to investigate these in detail and systematically understand the influence of surface conditions and the film formation process, we will apply standard characterizations of powders and films as well as specialized measurement techniques such as temperature-dependent photoluminescence (steady-state + time-resolved) and two-photon absorption photoluminescence. The optoelectronic properties of the powders are then compared with those of the layers processed (from the powders) and correlated with the respective process parameters selected for dry spraying and pressure treatment. It will be essential to recognize how the dry processing parameters have to be selected in order to achieve specific optoelectronic properties of the films and why these process parameters have to be selected that way.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Dr. Fabian Panzer, until 11/2022