Surface adsorption strategy enables bright green light-emitting Cs4PbBr6 nanocrystals@Al(H2PO4)3 phosphor for solid-state lighting

Abstract

Inorganic phosphate materials possess intriguing structural features which facilitate the smooth nucleation-growth and adsorption of light-emitting perovskite nanocrystals onto its surface. However, finding a suitable phosphate material and a proper method for growing halide perovskite (HP) nanocrystals (NCs) onto the surface of it is a tedious task due to the soft ionic nature of HPNCs. In this work, the spherical composite structures of Cs4PbBr6 NCs@AlP [AlP = aluminium dihydrogen phosphate, Al(H2PO4)3] are developed via nucleation and growth of Cs4PbBr6 NCs on the surface of AlP. The inherent adsorption capability of AlP opens up the possibility of adsorption of CsBr and PbBr2 on the large area surface of AlP, facilitating the nucleation-growth of Cs4PbBr6 NCs on the surface of bulk AlP. The synthesized Cs4PbBr6 NCs@AlP composite exhibits brighter green emission and enhanced humid stability than the bare one. As-a-proof of concept, we demonstrate intensive green LED fabricated by combining the synthesized phosphor, Cs4PbBr6 NCs@AlP with near-ultraviolet InGaN chip (λem = 395 nm). This work paves a new way for synthesizing spherical composite having long-term stability for optoelectronic devices.