Perovskite quantum dots (PQDs) attract significant interest in recent years because of their unique optical properties, such as tunable wavelength, narrow emission, and high photoluminescence quantum ...efficiency (PLQY). Recent studies report new types of formamidinium (FA) PbBr3 PQDs, PQDs with organic–inorganic mixed cations, divalent cation doped colloidal CsPb1−xMxBr3 PQDs (M = Sn2+, Cd2+, Zn2+, Mn2+) featuring partial cation exchange, and heterovalent cation doped into PQDs (Bi3+). These PQD analogs open new possibilities for optoelectronic devices. For commercial applications in lighting and backlight displays, stability of PQDs requires further improvement to prevent their degradation by temperature, oxygen, moisture, and light. Oxygen and moisture‐facilitated ion migration may easily etch unstable PQDs. Easy ion migration may result in crystal growth, which lowers PLQY of PQDs. Surface coating and treatment are important procedures for overcoming such factors. In this study, new types of PQDs and a strategy of improving their stabilities are introduced. Finally, this paper discusses future applications of PQDs in light‐emitting diodes.
Perovskite quantum dots (PQDs) have attracted much attention in recent years due to their unique optical properties, such as tunable wavelength, narrow emission, and high photoluminescence. They show amazing optical properties in two types of light‐emitting diode (LED) such as PQDs based white‐light LEDs and PQD‐QLED. It is hoped that the PQDs based LED can be used in next generation display and lighting applications.
All inorganic CsPbBr3 perovskite quantum dots (QDs) are potential emitters for electroluminescent displays. We have developed a facile hot‐injection method to partially replace the toxic Pb2+ with ...highly stable Sn4+. Meanwhile, the absolute photoluminescence quantum yield of CsPb1−xSnxBr3 increased from 45 % to 83 % with SnIV substitution. The transient absorption (TA) exciton dynamics in undoped CsPbBr3 and CsPb0.67Sn0.33Br3 QDs at various excitation fluences were determined by femtosecond transient absorption, time‐resolved photoluminescence, and single‐dot spectroscopy, providing clear evidence for the suppression of trion generation by Sn doping. These highly luminescent CsPb0.67Sn0.33Br3 QDs emit at 517 nm. A device based on these QDs exhibited a luminance of 12 500 cd m−2, a current efficiency of 11.63 cd A−1, an external quantum efficiency of 4.13 %, a power efficiency of 6.76 lm w−1, and a low turn‐on voltage of 3.6 V, which are the best values among reported tin‐based perovskite quantum‐dot LEDs.
Suppressed trion formation: CsPb1−xSnxBr3 quantum dots (QDs) were synthesized by a hot‐injection approach. As trion formation is suppressed by the SnIV substitution, light‐emitting diodes (LEDs) based on these highly luminescent QDs performed very well, with the highest current efficiencies and external quantum efficiencies ever reported for such Sn‐based systems.
All‐inorganic CsPbX3 (X=I, Br, Cl) perovskite quantum dots (PQDs) have been investigated because of their optical properties, such as tunable wavelength, narrow band, and high quantum efficiency. ...These features have been used in light emitting diode (LED) devices. LED on‐chip fabrication uses mixed green and red quantum dots with silicone gel. However, the ion‐exchange effect widens the narrow emission spectrum. Quantum dots cannot be mixed because of anion exchange. We address this issue with a mesoporous PQD nanocomposite that can prevent ion exchange and increase stability. We mixed green quantum‐dot‐containing mesoporous silica nanocomposites with red PQDs, which can prevent the anion‐exchange effect and increase thermal and photo stability. We applied the new PQD‐based LEDs for backlight displays. We also used PQDs in an on‐chip LED device. Our white LED device for backlight display passed through a color filter with an NTSC value of 113 % and Rec. 2020 of 85 %.
Points of light: Green CsPbBr3 perovskite quantum dots (PQDs), embedded in mesoporous silica (MP), were mixed with red CsPb(Br0.4I0.6)3 quantum dots in a silicone resin and placed on an InGaN blue chip. The green and red QDs were excited by blue light with λ=450 nm. The resulting PQD white light emitting diode (LED) exhibits a wide color gamut because of its narrow emission wavelength.
Perovskite Quantum Dot LEDs. In their Communication on page 7924 ff., R. S. Liu et al. describe the generation of a white LED device through excitation of a silicone resin containing green mesoporous ...silica‐CsPbBr3 and red CsPb(Br0.4I0.6)3 perovskite quantum dots with a blue InGaN chip.
All inorganic CsPbBr
perovskite quantum dots (QDs) are potential emitters for electroluminescent displays. We have developed a facile hot-injection method to partially replace the toxic Pb
with ...highly stable Sn
. Meanwhile, the absolute photoluminescence quantum yield of CsPb
Sn
Br
increased from 45 % to 83 % with Sn
substitution. The transient absorption (TA) exciton dynamics in undoped CsPbBr
and CsPb
Sn
Br
QDs at various excitation fluences were determined by femtosecond transient absorption, time-resolved photoluminescence, and single-dot spectroscopy, providing clear evidence for the suppression of trion generation by Sn doping. These highly luminescent CsPb
Sn
Br
QDs emit at 517 nm. A device based on these QDs exhibited a luminance of 12 500 cd m
, a current efficiency of 11.63 cd A
, an external quantum efficiency of 4.13 %, a power efficiency of 6.76 lm w
, and a low turn-on voltage of 3.6 V, which are the best values among reported tin-based perovskite quantum-dot LEDs.
Inorganic perovskite quantum dots (IPQD) assisted by a yellow emitting YAG:Ce phosphor were integrated on a blue LED chip. The red perovskite quantum dot (R-PQD) assisted YAG:Ce phosphors exhibit ...warm white light with CCT (3328 K), high color rendering index (CRI 84.7) and a super high value of saturated red color component R9 as 96. The results demonstrate that the inorganic red perovskite quantum dot assisted yellow phosphor material may be a potential candidate for the generation of warm white light for indoor lighting applications.
All inorganic CsPbBr3 perovskite quantum dots (QDs) are potential emitters for electroluminescent displays. We have developed a facile hot‐injection method to partially replace the toxic Pb2+ with ...highly stable Sn4+. Meanwhile, the absolute photoluminescence quantum yield of CsPb1−xSnxBr3 increased from 45 % to 83 % with SnIV substitution. The transient absorption (TA) exciton dynamics in undoped CsPbBr3 and CsPb0.67Sn0.33Br3 QDs at various excitation fluences were determined by femtosecond transient absorption, time‐resolved photoluminescence, and single‐dot spectroscopy, providing clear evidence for the suppression of trion generation by Sn doping. These highly luminescent CsPb0.67Sn0.33Br3 QDs emit at 517 nm. A device based on these QDs exhibited a luminance of 12 500 cd m−2, a current efficiency of 11.63 cd A−1, an external quantum efficiency of 4.13 %, a power efficiency of 6.76 lm w−1, and a low turn‐on voltage of 3.6 V, which are the best values among reported tin‐based perovskite quantum‐dot LEDs.
Unterdrückte Trionenbildung: CsPb1−xSnxBr3‐Quantenpunkte (QDs) wurden durch Heißinjektion synthetisiert. Da die Trionenbildung durch die SnIV‐Substitution unterdrückt wird, haben Leuchtdioden (LEDs) auf Basis dieser lumineszierenden QDs die höchsten Stromausbeuten und externen Quanteneffizienzen, die je für solche Sn‐basierten Systeme beschrieben wurden.
All‐inorganic CsPbX3 (X=I, Br, Cl) perovskite quantum dots (PQDs) have been investigated because of their optical properties, such as tunable wavelength, narrow band, and high quantum efficiency. ...These features have been used in light emitting diode (LED) devices. LED on‐chip fabrication uses mixed green and red quantum dots with silicone gel. However, the ion‐exchange effect widens the narrow emission spectrum. Quantum dots cannot be mixed because of anion exchange. We address this issue with a mesoporous PQD nanocomposite that can prevent ion exchange and increase stability. We mixed green quantum‐dot‐containing mesoporous silica nanocomposites with red PQDs, which can prevent the anion‐exchange effect and increase thermal and photo stability. We applied the new PQD‐based LEDs for backlight displays. We also used PQDs in an on‐chip LED device. Our white LED device for backlight display passed through a color filter with an NTSC value of 113 % and Rec. 2020 of 85 %.
Punktstrahler: In mesoporöses Siliciumoxid (MP) eingebettete grüne Perowskit‐Quantenpunkte (PQDs) aus CsPbBr3 wurden mit roten CsPb(Br0.4I0.6)3‐Quantenpunkten in einem Siliconharz gemischt und auf einen blauen InGaN‐Chip aufgebracht. Die grünen und roten QDs wurden mit blauem 450‐nm‐Licht angeregt. Die resultierende Weißlicht‐emittierende PQD‐Leuchtdiode zeigt wegen ihrer engen Emissionswellenlänge einen breiten Farbbereich.
Perowskit‐Leuchtdioden. Die weiße LED‐Einheit, die R. S. Liu et al. in ihrer Zuschrift auf S. 8056 ff. vorstellen, beruht auf der Anregung eines Siliconharzes, das grüne Quantenpunkte aus mesoporösem ...Siliciumdioxid‐CsPbBr3 und rote CsPb(Br0.4I0.6)3‐Perowsit‐Quantenpunkte enthält und sich auf einem blauen InGaN‐Chip befindet.
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