Luminescent solar concentrator comprising tetra-substituted benzoheterodiazole compounds

A luminescent solar concentrator (LSC) comprising at least one tetra-substituted benzoheterodiazole compound having general formula (I): wherein: R1 and R2, equal to or different from each other, are selected from: C6-C40, preferably C6-C20 aryl groups, optionally substituted; C4-C40, preferably C5-C20, heteroaryl groups, optionally substituted; R3 and R4, equal to or different from each other, are selected from: halogen atoms such as, for example, fluorine, chlorine, bromine, iodine, preferably fluorine; linear or branched C1-C30, preferably C1-C20, trihalogenated alkyl groups; C6-C40, preferably C6-C20, aryloxyl groups optionally substituted; linear or branched C1-C30, preferably C1-C20, alkoxyl groups optionally substituted; C4-C40, preferably C5-C20, heteroaryloxyl groups optionally substituted; Z represents a sulfur atom, an oxygen atom or a selenium atom; a NR5 group wherein R5 represents a hydrogen atom, or it is selected from linear or branched C1-C24, preferably C6-C24, alkyl groups, optionally containing heteroatoms; a CR6R7 group wherein R6 and R7, equal to or different from each other, represent a hydrogen atom, or they are selected from linear or branched C1-C30, preferably C6-C24, alkyl groups, optionally containing heteroatoms, linear or branched C1-C30, preferably C6-C24, alkoxyl groups, optionally substituted, C3-C30, preferably C4-C24, cycloalkyl groups, optionally substituted, or, R6 and R7 can be optionally bound to each other to form, together with the other atoms to which they are bound, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted with linear or branched C1-C30, preferably C1-C15, alkyl groups, said cycle optionally containing heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorous, selenium.