Luminescent quantum dots (QDs) and perovskite nanocrystals (PNCs) are promising, efficient energy converters for advanced displays and light sources. Their widespread applications in the photoluminescence (PL)-based displays have been achieved through color enhancement films and patterned color-converters. Meanwhile, electroluminescence (EL) devices based on QDs and PNCs are still under active development, but emerging applications in the healthcare domains could accelerate their adoption. Herein, we first analyze the QD color-conversion displays guided by state-of-the-art research and then summarize the evolution of in situ strategies to fabricate efficient and stable PNC–polymer composites. Subsequently, we introduce the application of flexible QD light-emitting devices for healthcare as a potential early target market. Remaining challenges and future perspectives of QDs and PNCs as light-converters for PL displays, and of QDs for EL applications in healthcare, are analyzed.

Stretch-alignment of CsPbBr₃ perovskite nanorods synthesized in situ in a polymer matrix leads to polarized emission.

We propose to use a hybrid downconverter system comprising low-cost green perovskite-polymer composite films for liquid crystal display (LCD) backlight unit (BLU) to realize wide color gamut. Recently, ultrastable, highly luminescent CH₃NH₃PbBr₃ (MAPbBr₃) organic-inorganic perovskite-polymer composite films have been developed. These films exhibit outstanding color quality with a full-width-at-half-maximum (FWHM) of only 18 nm and a peak wavelength of 530 nm, which makes them promising candidates as green downconverters. Two configurations to hybridize these green films with state-of-the-art red emitting downconverters, including CdSe-based quantum dots (QDs) and narrow peak phosphors, are proposed. Color and efficiency analyses indicate that the hybridization of green perovskite-polymer films with red K₂SiF₆:Mn⁴⁺ (KSF) phosphor could lead to wide color gamut coverage of nearly 90% Rec. 2020 and high total light efficiency (TLE) of around 20 lm/W while maintaining low cost.

Recent advances in perovskite nanocrystals-enhanced solid-state lighting (SSL) and liquid-crystal displays (LCDs) are reviewed. We first discuss the development, optical properties, and stability issue of materials, and then we evaluate the performance of SSL and LCDs with perovskite downconverters adopted. In SSL performance evaluation, we investigate the fitting-curve effect in calculations and optimizations where simple Gaussian fitting and precise fitting are compared in detail, and we further optimize for highly efficient, good color-rendering, and human-healthy SSL sources. For LCD performance evaluation, we study the intrinsic tradeoffs between total light efficiency and color gamut coverage. Through optimizations using real line shapes, Rec. 2020 standard coverage as large as 92.8% can be achieved through hybrid integration. Finally, we briefly discuss two future challenges: materials development and device integration. We believe the emerging perovskite nanocrystals are highly promising for next-generation SSL and LCDs.