Thermionic emission measurement of sintered lanthanum hexaboride discs and modelling of their solar energy conversion performance
Authors: Bellucci A., Mastellone M., Girolami M., Serpente V., Sani E., Sciti D., Trucchi D.M.
Autors Affiliation: a Istituto di Struttura della Materia, ISM-CNR, Sede Secondaria di Montelibretti, DiaTHEMA Lab, Via Salaria km 29.300, 00015, Monterotondo, RM, Italy
b Istituto Nazionale di Ottica, INO-CNR, Largo E. Fermi, 6, Firenze, FI, I-50125, Italy
c Istituto di Scienza e Tecnologia dei Materiali Ceramici, ISTEC-CNR, Via Granarolo 64, 48018, Faenza, RA, Italy
Abstract: Polycrystalline lanthanum hexaboride (LaB6) discs were sintered by hot pressing of commercial powders and successively polished, in order to investigate their thermionic emission capability. LaB6 samples presented values of work function in the range 2.55-2.61 eV. Discs with polished surface, independently from the composition and density, demonstrated to provide a Richardson constant around 45 A cm-2 K-2. These results are promising for the use of sintered LaB6 discs in thermionic energy converters operating at temperatures in the 1400-1700 degrees C range. Moreover, since the properties of solar absorption and spectral selectivity of LaB6 make them appealing for the conversion of concentrated solar radiation, a modelling study to estimate the energy conversion efficiency was performed, aimed at identifying the proper engineering strategies able to make the resulting devices competitive for electrical conversion of concentrated solar radiation.
Journal/Review: CERAMICS INTERNATIONAL
Volume: 47 (14) Pages from: 20736 to: 20739
KeyWords: Thermionic emission
Concentrated solar radiation
Solar-to-electric conversion efficiency
Surface properties DOI: 10.1016/j.ceramint.2021.04.079Citations: 3data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2022-06-26References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here