Beyond OLED: Efficient Quantum Dot Light‐Emitting Diodes for Display and Lighting Application

Abstract

The unique features of solution-processed quantum dots (QDs) including emission tunability in the visible range, high-quality saturated color and outstanding intrinsic stability in environment are highly desired in various application fields. Especially, for the preparation of wide color gamut displays, QDs with high photoluminescence quantum yield are deemed as the optimal fluorescent emitter that has been utilized in the backlight for liquid crystal display. Nevertheless, the commercialization of electrically driven self-emissive quantum dot lightemitting diode (QLED) display is the ultimate target due to its merits of high contrast, slim configuration and compatibility with flexible substrate. Through the great efforts devoted to material engineering and device configuration, astonishing progresses have been made in device performance, giving the QLED technology a great chance to compete with other counterparts for next-generation displays. In this review, we retrospect the development roadmap of QLED technology and introduce the essential principles in the QLED devices. Moreover, we discuss the key factors that affect the QLED efficiency and lifetime. Finally, the advances in device architectures and pixel patterning are also summarized.

Emergence of Impurity-Doped Nanocrystal Light-Emitting Diodes

“…Recently, Ji et al also demonstrated that CQD-LEDs with all-inorganic device architectures could possess a high efficiency (20.5 cd A −1 ) and impressive luminance (20,000 cd m −2 ) simultaneously, where nickel oxide (NiO) and zinc oxide (ZnO) were used as HTL and ETL, respectively [ 151 ]. However, relatively few effective inorganic charge transporting materials are available, which restricts the further development of this type of device architecture [ 152 ].…”

65‐3: Green Top‐emission Quantum Dot Light‐emitting Diodes (TE‐QLED) with Normal and Inverted Structure

“…Colloidal quantum dot light-emitting diodes (QLEDs) have drawn much attention due to its unique properties (i.e. tunable color emission spectrum, narrow emission bandwidth and low driving voltage, simple fabrication process) and these advantages make QLED be considered a candidate for next generation display technology [1][2][3][4][5][6][7][8][9][10][11]. For real application, the device performance is important.…”

Light extraction from quantum dot light emitting diodes by multiscale nanostructures

“…[5][6][7] The technical challenge of QLED devices is that their EQE is limited by the light outcoupling efficiency of the device, which is indeed unresolved because of total internal reection, waveguide (WG) and metal surface absorption (SPP). 8,9 Numerous studies have reported that the light extractions of OLEDs and QLEDs could be enhanced through introduction of internal or external light-extraction layers. [10][11][12][13][14] For example, we have demonstrated that introducing internal PEDOT:PSS grating nanostructures can effectively extract the waveguided light from QLEDs by nanoimprint lithography techniques.…”