The invention provides a lighting unit (100) comprising a light source (10), configured to generate light source light (11) and a luminescent material (20), configured to convert at least part of the light source light (11) into luminescent material light (51), wherein the luminescent material (20) comprises a phosphor (40), wherein this phosphor comprises an alkaline earth aluminum nitride based material having a cubic crystal structure with T5 supertetrahedra, wherein the T5 supertetrahedra comprise at least Al and N, and wherein the alkaline earth aluminum nitride based material further comprises a luminescent lanthanide incorporated therein.

An emissive material includes a source of alumina in an amount between about 20 and about 30 weight % (wt. %), B.sub.4C in an amount between about 10 and about 20 wt. %, and SiC in an amount between about 55 and about 65 wt. %.

A composition is provided which is useful for the production of a cured product which is excellent in heat resistance and light permeability. The composition includes a polysiloxane, at least one alkoxysilane partial condensate having no hydroxyl group selected from the group consisting of a T-type alkoxysilane partial condensate having no hydroxyl group and a Q-type alkoxysilane partial condensate having no hydroxyl group, and a phosphoric acid-based catalyst. The polysiloxane is represented by the following formula (1):

##STR00001##

In formula (1), m represents an integer of 5 to 3000 and R.sup.1 represents an alkyl group. The plurality of R.sup.1 may be the same or different.

The present invention relates to a novel composite of graphene quantum dot and silica. The present invention further relates to a novel one step process for the synthesis of composite of GQD and silica from paper. The composite is useful for biological applications such as bioimaging, drug delivery etc.

The invention provides a lighting unit (100) comprising a light source (10), configured to generate light source light (11) and a luminescent material (20), configured to convert at least part of the light source light (11) into luminescent material light (51), wherein the luminescent material (20) comprises a phosphor (40), wherein this phosphor comprises an alkaline earth aluminum nitride based material having a cubic crystal structure with T5 supertetrahedra, wherein the T5 supertetrahedra comprise at least Al and N, and wherein the alkaline earth aluminum nitride based material further comprises a luminescent lanthanide incorporated therein.