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

Inorganic CsPbX3 perovskite quantum dots (PQDs) have attracted considerable attention in light-emitting diodes (LEDs) due to their great photoluminescent properties. Despite the excellent progress of PQDs in red and green emission, the application of blue−emitting PQDs is limited by low photoluminescence quantum yield (PLQY) and weak stability. To address this problem, this study reports on 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 greatly enhanced from 37% to 54%, accompanying excellent stability in a variety of extreme environments, such as UV light, high temperature, and polar solvents as well as at room temperature storage.