Conversion of UV light to dazzling reddish orange light with robust color purity for plant growth in biocompatible glasses

Remarkable red luminescence was achieved from synthesized lithium zinc borate glasses (LBZ) composed of Eu ³⁺ and Gd ³⁺ ions by melt quenching for greenhouse applications. LBZ: Gd ³⁺ glass exhibited emission at 311 nm ( ⁶P _7/2→ ⁸S _7/2) upon 265 nm excitation. By exciting at 393 nm, LBZ: Eu ³⁺ glass emits a dazzling reddish-orange emission at 612 nm ( ⁵D ₀→ ⁷F ₂). Due to successful energy migration from Gd ³⁺ to Eu ³⁺, co-doped glasses generate more exquisite reddish light at 612 nm with high color purity than independently (Eu ³⁺) doped glass under 265 nm of UV irradiation. Various fluorescence methods were used to demonstrate energy transmission. Notably, the enhanced luminescence extending from 580 to 700 nm pertaining to co-doped glasses was correlated with the absorption spectrum of chlorophyll. The results of in vitro cell viability confirm the non-cytotoxicity and a high level of biocompatibility. From the results, the non-cytotoxic co-doped (1.0Gd ³⁺-1.0Eu ³⁺)-glass has been found to be a potential candidate as a biocompatible greenhouse glass for plant growth.