Executive Summary – Stage 1 (September–December 2025)
Stage 1 of the OPTOCARSEMO project established the scientific, methodological, and experimental foundations required for multi-modal, multi-scale characterization of mixed semiconductor oxides (SMOs). The work focused on two major components: selection of materials (Task 1.1) and integration of characterization infrastructures and methodologies between UTM and PB (Task 1.2).
Task 1.1 – Selection of Mixed Semiconductor Oxides
A comprehensive and systematic analysis was conducted to identify the SMO materials best suited for subsequent investigations. The process included a critical review of recent international literature, an assessment of compatibility with available experimental techniques, and the establishment of multicriteria selection rules.
The analysis highlighted the relevance of base oxides such as ZnO, CuO, TiO₂, Fe₂O₃, as well as mixed systems including ZnO–CuO, TiO₂–ZnO, ZnFe₂O₄, TiO₂–Fe₂O₃, owing to their optical, electronic, and structural properties of high interest for sensing and optoelectronic applications. Dopants such as Au, Ag, Ni, and Al were will also be prioritized in forthcoming work due to their strong influence on plasmonic enhancement and local conductivity—critical aspects for advanced near-field techniques such as TERS and s-SNOM.
The outcome of Task 1.1 consists of a rigorously documented material portfolio and a set of selection criteria optimized for the project’s experimental objectives. This portfolio forms the basis for synthesis and detailed characterization planned in Stage 2 (January-December 2026). A Review-type article covering this field, is currently in preparation.
Task 1.2 – Integration of UTM and PB Characterization Platforms
Task 1.2 addressed the integration of two distinct yet complementary experimental ecosystems. Extensive calibration campaigns were performed on UTM instruments (SEM, XRD, Raman, EDX) and on Politehnica’s advanced imaging systems operating in the far-field and near-field regimes, including on homemade multimodal platforms for correlative imaging which uniquely combines a wide variety of far-field and near-field optical nanoscopy techniques, based on CW and non-linear excitation, complemented by possibilites for topographic imaging at nanoscale enabled by Atomic Force Microscopy.
Joint protocols were created for sample preparation, data acquisition, probe handling, and secure sample transfer between institutions. A unified framework for metadata, file formats, and data processing workflows was also established to ensure seamless interoperability.
A major achievement of this task was the definition of four correlative characterization pathways, linking macro-, micro-, and nano-scale techniques in a coherent manner—for example, XRD–SEM–Raman transitioning into TERS/s-SNOM, or Raman–AFM transitioning into TERS–TAM. These pathways enable a structured approach to exploring crystalline phases, morphology, defect distribution, and nanoscale optical responses.
Cross-laboratory tests on reference samples confirmed the reproducibility and alignment of methodologies, demonstrating that UTM and PB facilities can results at the end of this Task, to be completed in 2026, into a cohesive, integrated characterization ecosystem.
Overall Conclusion
Stage 1 successfully delivered all foundational components required for the project’s scientific progression: a well-defined SMO material set, calibrated and interoperable instrumentation, standardized protocols, and robust correlative workflows. These results position the project for efficient execution of synthesis and advanced characterization activities to be implemented in Stage 2 (January-December 2026)