All–Inorganic Perovskite Quantum Dot–Based Blue Light–Emitting Diodes: Recent Advances and Strategies

Abstract

Light–emitting diodes (LEDs) based on all–inorganic lead halide perovskite quantum dots (PQDs) have undergone rapid development especially in the past five years, and external quantum efficiencies (EQEs) of the corresponding green– and red–emitting devices have exceeded 23%. However, the blue–emitting devices are facing greater challenges than their counterparts, and their poor luminous efficiency has hindered the display application of PQD–based LEDs (PeQLEDs). This review focuses on the key challenges of blue–emitting PeQLEDs including low EQEs, short operating lifetime, and spectral instability, and discusses the essential mechanism by referring to the latest research. We then systematically summarize the development of preparation methods of blue emission PQDs, as well as the current strategies on alleviating the poor device performance involved in composition engineering, ligand engineering, surface/interface engineering, and device structural engineering. Ultimately, suggestions and outlooks are proposed around the major challenges and future research direction of blue PeQLEDs.

Effect of polymethyl methacrylate on in situ patterning of perovskite quantum dots by inkjet printing

“…Perovskite quantum dots (PQDs) have attracted great attention due to their unique optical and electronic properties such as high luminous quantum yield, tunable emission wavelength, and excellent charge transport properties [1][2][3][4][5][6]. Inkjet printing is considered a promising method for preparing PQDs patterns due to its high throughput, low cost, and simple process [7][8][9][10][11].…”

Eliminating Chlorine Vacancies of Perovskite Nanocrystals Using Hydrazine Cations Enables Efficient Pure Blue Light-Emitting Diodes

“…Currently, sky blue light (∼490 nm) perovskite LEDs have been reported with efficiencies exceeding 15%. , Nevertheless, as the wavelength decreases toward pure blue, ranging between 465 and 475 nm, a notable decline in device efficiency is observed. − The primary challenges faced by pure blue perovskite LEDs are low efficiency, short lifetime, and poor spectral stability. These issues primarily stem from the challenging electrical injection resulting from the wide bandgap and efficiency loss caused by high-density deep traps. − Consequently, the development of high-quality pure blue perovskite emitters with low defects and minimal traps is crucial for achieving efficient and stable pure blue perovskite LEDs.…”