**4. Conclusions**

A new hybrid material has been designed herein by simultaneous encapsulation in appropriate amounts of three dyes, acridine (AC), pyronin Y (PY), and LDS722, with complementary spectroscopic bands emitting in the blue, green, and red regions of the visible spectrum, into the 1D-Mg-containing aluminophosphate framework with AEL structure, revealing an efficient white light emission under UV irradiation.

The final color is a consequence of successive partial energy transfer processes among the dyes, which can be modulated by the final uptake of each dye in the host matrix. Once the initial dye ratio

is optimized in the synthesis gel, this straightforward synthesis through the one-pot occlusion of the chromophores offers an easy and fast approach to render a solid-state system with pure white light emission and an efficiency of around 20%. This type of hybrid material offers versatile white light emitter systems in which their brightness and emission color purity can be easily tuned. More importantly for future commercial applications, this material is easy and inexpensive to manufacture, and the process is not time-consuming since the incorporation of the dyes and synthesis of the hybrid material takes place in a unique step.

**Author Contributions:** Synthesis of the materials, A.A., L.G.-H., and J.P.-P.; Characterization of the materials, R.S.-L., A.O.-S., T.A., J.H., and E.F.; Conceptualization, R.S.-L. and V.M.-M.; writing—original draft preparation, R.S.-L., V.M.-M., and E.F.; writing—review and editing, V.M.-M. and E.F.; supervision, V.M.-M.; funding acquisition, V.M.-M. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by Gobierno Vasco (IT912-16), Ministerio de Economía y Competitividad (MINECO), the Spanish Agencia Estatal de Investigación, and the EU's Fondo Europeo de Desarrollo Regional under projects MAT2017-83856-C3-3-P and MAT2016-77496-R, and C1/C2 KU Leuven, FuEPoNa (3E190382).

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

**Appendix A**

**Figure A1.** XRD patterns of AEL materials, without dyes (**bottom**), Sample 4 (**middle**), and Sample 5 (**top**); \* indicates minor impurities of AFI material.

**Figure A2.** Time-resolved fluorescence emission spectra of Sample 4 recorded by fs fluorescence up-conversion in 50 ps time window (λexc = 395 nm).

**Figure A3.** Time-resolved fluorescence emission spectra of Sample 5 recorded by fs fluorescence up-conversion in 50 ps time window (λexc = 395 nm).

**Figure A4.** Changes in the CIE coordinates of Sample 4 at different times of intense UV irradiation (λexc = 355 nm and an irradiance of 2.75 mW/cm2): t = 0 (point 1); t = 1 h (point 2) and r = 6 h (point 3).
