Rare-Earth Gadolinium (Gd)-Doped InP Quantum Dots with Excellent Photostability in Liquid Crystal Display Backlight Display

Quantum dots (QDs) were emerging as compelling candidates for optoelectronic applications, attributed to their unique size-tunable optical characteristics, narrow emission spectra, and superior photoluminescent quantum yield (PLQY). Notably, the low toxicity of InP materials makes them a promising alternative in the field of environmentally friendly optoelectronic components compared to QDs containing toxic elements (such as Cd, Hg, and Pb). However, synthetic conditions of InP QDs were extremely harsh, and the reagents were very expensive. In this study, we reported a new method for the synthesis of Gd-doped InP/ZnSe/ZnS QDs by using two inexpensive and low-reactivity phosphine precursors as the phosphorus source at a lower temperature. The InP QDs were synthesized via a one-pot solvothermal method, incorporating rare-earth Gd ions as dopants during the core growth process, and the influence of Gd doping on their stability was investigated. Gd:InP/ZnSe/ZnS QDs exhibited improved stability, as evidenced by their enhanced resistance to photo- and thermal degradation. And first-principles method reveals that Gd doping introduces shallow trap states that effectively passivates surface defects, which contribute to the overall stability of quantum dots. Furthermore, Gd:InP/ZnSe/ZnS QDs were integrated into QDs enhanced film (QDEFs) for LCD backlight display with excellent reliability performance over 2000 h.