Two-step modification of high-performance inorganic perovskite quantum dots for blue light emission

Abstract

Inorganic CsPbX₃ perovskite quantum dots (PQDs) have attracted considerable attention in light-emitting diodes (LEDs) due to their excellent photoluminescent properties. Despite the excellent progress of PQDs in red and green emissions, the application of blue-emitting PQDs is limited by their low photoluminescence quantum yield (PLQY) and weak stability. To address this problem, this study presents a strategy that combines anionic post-exchange with surface passivation. High performance blue-emitting PQDs were obtained through anion exchange using 1,3-dimethylpentylamine hydrochloride (DPE), followed by passivation with trifluoroacetate groups (CF₃COO⁻) and octylamine groups (OLAH⁺). The PLQY of PQDs is significantly enhanced from 37% to 54%, accompanied by excellent stability under extreme conditions, such as UV light, high temperature, polar solvents and room temperature storage.