Summary

The development of alternative processes for fabrication and integration of functional nano-materials in complex optoelectronic semiconductor systems, such as organic light-emitting diodes or thin-film solar cells, has a very high scientific value in the context of the energy transition and the lack of semiconductors made of rare earth materials. The non-aqueous sol-gel synthesis route (NAR) in the liquid phase delivers a particularly suitable, cost-effective and well controllable process route for the production of a broader variety of highly functional and crystalline metal oxides (MeO) having adjustable particle properties (sizes, morphologies) for the specific modification of the product properties (conductivity, optics), e.g., for aluminum-doped zinc oxide (AZO). To control the NAR process the application of diverse measurement technologies with access to time-resolved process characterization is required and thus provides excellent preconditions for their real time integration into an autonomous process control system. Analysis and control of particle processes typically relies on suitable process models that in general consist of one- or multi-dimensional partial integro-differential equation, i.e., the population balance, and one or multiple ordinary differential equations to represent mass and energy balances of the liquid phase. These first principle models are completed by constitutive equations, nucleation and growth kinetics as well as breakage and aggregation relationships. The final goal of the present proposal is the development, realization and evaluation of a novel autonomous multi-purpose process control scheme for the fabrication process of highly crystalline MeO via NAR and to investigate its extension to combined process and property control for general particle processes following the sol-gel route. The experimental part of the proposal is handled by the Institute of Mechanical Process Engineering at the Karlsruhe Institute of Technology (Prof. Hermann Nirschl) and the control aspects will be developed by the Chair of Automation and Control at the Kiel University (Prof. Thomas Meurer).