Incorporation of zinc ions towards low toxicity and high stability of organic-inorganic methyl ammonium lead bromide perovskite QDs via ultrasonication route for white-LEDs

Doping Strategies for Promising Organic-Inorganic Halide Perovskites

Organic-inorganic halide perovskites (OIHPs) obtained tremendous attention due to their low cost and excellent properties. However, the stability and toxicity of Pb-based OIHPs (POIHPs), as well as the weakness of efficiency and stability in Sn-based OIHPs (SOIHPs), are still serious issues for commercial application. Notably, composition engineering is an effective and direct strategy for improving these issues along with the control and modification of properties. Recently, the doping strategies for POIHPs and SOIHPs are booming. Based on the relationship between properties and composition, the doping strategies for POIHPs and SOIHPs, aiming to provide a comprehensive review and guidance for the research are systematically summarized. Moreover, the doping strategies for Pb-Sn mixed OIHPs are also discussed. Finally, a brief perspective and conclusion toward future possible doping schemes and properties designment of POIHPs and SOIHPs are offered.

Progress of Backlight Devices: Emergence of Halide Perovskite Quantum Dots/Nanomaterials

The technology behind the display is becoming ever more prevalent in our daily lives. It has many applications, including smartphones, tablets, desktop monitors, TVs, and augmented reality/virtual reality devices. The display technology has progressed drastically over the past decade, from the bulky cathode ray tube to the flat panel displays. In the flat panel displays, the liquid crystal display (LCD) and organic light-emitting diodes (OLEDs) are the two dominant technologies. Nevertheless, due to low stability and color tunability, OLEDs remain behind the LCDs. The LCD screen has a backlight, usually a white LED, which comprises a blue LED covered with a red and green enhanced layer (color-converting layers). Although InP/CdSe QDs attracted more attention due to their solution processability and better color gamut than the previous technologies, the complexity of their synthesis was still an obstacle to their commercialization. Later, the emergence of perovskite with highly intense and tunable PL emission, high color purity, and low-cost synthesis route attracted the attention of display researchers. Owing to the relatively higher performance of perovskite quantum dots (PQDs) than that of bulk (3D) perovskite in backlit display devices, these PQDs are being used for high color contrast and bright display devices. Furthermore, the color gamut for PQDs was observed as 140% of the NTSC standard, that is, close to that of the commercial OLED devices. In this review, we have discussed the progress of display technologies with a clear classification of the pros and cons of each technology. Also, the application of perovskite QD/nanomaterials in LCD backlit devices has been discussed, and the future direction of further improvement in their stability and performance has been listed.