White light-emitting diodes based on carbon dots and Mn-doped CsPbMnCl₃ nanocrystals

Abstract

CsPbX 3 perovskite nanocrystals (NCs) are becoming a promising material for optoelectronic devices that possess an optically tunable bandgap, and bright photoluminescence. However, the toxic Pb is not environmentally friendly and the quantum yield (QY) of blue emitting NCs is relatively low. In addition, the red emitting perovskite containing iodine is not stable under light illumination. In this paper, high QY, blue emitting, non-toxic fluorescent nanomaterial carbon dots and orange-emitting CsPb 0.81 Mn 0.19 Cl 3 NCs with partial Pb replacement are combined to fabricate white light-emitting diodes (WLEDs). A WLED with color coordinates of (0.337, 0.324) and a correlated color temperature of 4804 K is fabricated. Compared to red emitting perovskite containing iodine, the CsPb 0.81 Mn 0.19 Cl 3 NCs are stable no matter whether they are stored in the air or exposed under ultraviolet light. Therefore, the as-fabricated WLED shows good color stability against increasing currents and long-term working stability.

Integration of Environmental Friendly Perovskites for High-efficiency White Light-emitting Diodes

“…5b and c). The highest luminous efficiency and luminance of the WLED reach up to 20.8 lm/W and 78,000 cd m −2 , respectively, which are comparable with other UV chip-based WLEDs [4, 37–39].

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“…In general, WLEDs were recognized as one kind of the economical and efficient solid-state lighting sources [2, 3]. QD-LED technology is gradually developed over the past few years, because of high stability and high quantum yield (QY) of quantum dots (QDs) [4]. Recently, perovskites have attracted much attention, and they have been applied in many different fields [5–15].…”

Tunable Carbon–CsPbI3 Quantum Dots for White LEDs

“…White light-emitting diodes (WLEDs) are currently dominating the illumination market and have become a strong contender into the future promising lighting sources for the next generation backlighting components in the display technology. [1,2] The actual strategies for the fabrication of WLEDs consist in the combination of commercial InGaN blueemitting chips such as back illumination, and yellow converters based on inorganic phosphors doped with lanthanide/rare earths ions such as YAG:Ce 3+ , Ba 3 SiO 5 :Eu 2+ ; [3,4] or of ultraviolet LED coated with red, green and blue phosphors. [5,6] Halide perovskites quantum dots (PQDs) owing to their high photoluminescence quantum yield (PLQY), [7] and tunable bandgap covering the entire visible spectral range and color purity, have reached considerable attention on the development of LEDs.…”

“…[13] In this context, although PQDs offer a PLQY up to 100% and the color rendering index (CRI) of the PQD mixtures to produce white color can be >80%, the PLQY of the mixture is still far from unity (<70%). [4,14] Clearly, this is an indication that there is a lot of room to improve the white emission. Thus, it is essential to find suitable materials that can provide efficient red, blue, and green (RGB) emission in order to obtain a broadband emission for producing a stable white light.…”

Emergence of Impurity-Doped Nanocrystal Light-Emitting Diodes

“…By virtue of impurity doping, the electronic, optical, catalytic, transporting and magnetic properties of nanocrystals can be controlled to satisfy the requirement of optoelectronic and microelectronic applications. With the gradual comprehending of the effect of impurity doping (e.g., enhancing synthesis control over impurity incorporations, studying the concentrations, and exploring emerging phenomena), the development of impurity-doped nanocrystal LEDs is flourishing [ 329 , 330 , 331 ]. Nowadays, impurity-doped nanocrystal LEDs can possess many exceptional merits (e.g., enhanced efficiency, improved luminance, reduced driving voltage, and prolonged lifetime), making them highly promising for the future-generation displays, lighting, and signaling.…”