Description
Highly efficient photoluminescent (PL) (fluorescent) materials – often based on semiconductor quantum dots or organic dyes are important many applications from lighting (luminophors, phosphors) to solar-light harvesting (luminescent converters and concentrators). In this contribution, we present our innovative radiometry set-ups and methods, namely the portable set-up for determination of yield and efficiency of luminescent materials directly under the solar-illumination [1]. This portable set-up is currently applied for studies of the day-time radiative-cooling layers fabricated in our laboratory or from external suppliers. We are developing methodologies for the most relevant and complete optical characterization of tested materials necessary for modelling and assessment of these materials. Other laboratory radiometry set-ups (mostly including integrating spheres [2]) were developed for measurement of absolute quantum yield over broad spectral range and enable to solve some difficult tasks, like e.g. the measurements of anti-Stokes luminescence quantum yield [3].
This project was supported by the Czech Science Foundation (project 23-06.
[1] J. Valenta, A. Fucikova, M. Greben, H. Saeed Khan, R. Paolini, S. Garshasbi, M. Santamouris: Radiometric characterization of daytime luminescent materials directly under the solar illumination. AIP Advances 14, 105113 (2024).
[2] Jan Valenta: Integrační koule – podivuhodně jednoduchý a užitečný optický prvek. Čs. čas. fyz. 76, 188–195 (2026).
[3] J. Valenta, M. Greben, T. Takagi, M. Vacha: Photoluminescence Emitter with 100% Power Efficiency – The Key Role of the Absorption Edge in CsPbBr3 Perovskite Quantum Dots. ACS nano 20, 14709–14716 (2026).