Provided is a nanocrystal comprising a core comprised in a shell, wherein the core comprises a first material of a perovskite structure comprising a first organic cation not exceeding a molar weight of about 45 g/mol, a first divalent metal and a first counter anion, and, wherein the shell comprises a second material of a perovskite structure comprising a second organic cation having a molar weight between about 74 g/mol and about 187 g/mol, optionally the first organic cation, a second divalent metal and a second counter anion. Provided is further a matrix having the nanocrystal as defined above encapsulated therein. Provided is further a process for the synthesis of a nanocrystal comprising a core comprised in a shell, the process comprising a) preparing a precursor solution containing at least one divalent metal, a first organic cation not exceeding a molar weight of about 45 g/mol, a second organic cation having a molar weight between about 74 g/mol and about 187 g/mol, and at least one counter anion in a polar aprotic solvent; and b) subjecting the precursor solution to a non-polar solvent to form the nanocrystal.