UV-Green Emission from Organolead Bromide Perovskite Nanocrystals

Abstract

Ultraviolet (UV)-green emitting MAPbBr3 nanocrystals were synthesized at room temperature, employing a cost-effective solution-based method. The size control of nanocrystals was achieved through varying ligand and solute concentrations, which resulted in a tunable band gap and emission spectrum. The growth mechanism as well as the effect of ligand concentration on the structural and optical properties were studied in detail. The excitation spectra extended from the blue to UV region. This indicates that these perovskites are promising photon down conversion materials, which can combine with III-nitride UV/blue light-emitting diodes (LEDs) to emit white light. This work may bring III-nitride-based white LEDs one step closer to widespread adoption in general illumination market because the large emission range that has been produced with the ligand-assisted reprecipitation process is an important milestone in the path to justifying commercialization.

Tetradic phosphor white light with variable CCT and superlative CRI through organolead halide perovskite nanocrystals

“…Lead halide perovskites and their mixed-halide composites are emerging as a new generation of economic and scalable materials [12][13][14][15][16] due to their favourable optoelectronic properties such as strong absorption coefficients, 17,18 broadband excitation, 19,20 narrow band emission, 21,22 broad color gamut, 23,24 high quantum yield, [25][26][27][28] and tunable bandgap. [29][30][31][32][33] These properties attest to their future applicability in solid-state devices and may lead to rapid improvement in the performance of optoelectronic devices such as LEDs, [34][35][36][37][38] solar cells, [39][40][41][42] photodetectors, 43,44 and lasers.…”

Electrochemical p-Doping of CsPbBr3 Perovskite Nanocrystals

“…Since the discovery of lead halide perovskite nanocrystals (NCs) in 2014, 1 these materials have been investigated as candidates for downconversion phosphors, 2 − 4 absorber layers in solar cells, 5 − 7 and emitting layers in light-emitting diodes (LEDs). 8 − 14 Important advantages of perovskite NCs are their facile synthesis 15 − 18 and their intrinsic defect tolerance.…”

Mn4+-activated oxyfluoride K3TaOF6 red phosphor with intense zero phonon line for warm white light-emitting diodes

“…Obviously, an intense ZPL was recorded at about 620 nm, credited to the extremely distorted coordination environment of Mn 4+ ions. The PLE spectrum detecting at 628 nm shows two wide excitation bands at 470 nm and 370 nm, assigned to the spin-allowed 4 A 2g / 4 T 2g and 4 A 2g / 4 T 1g transitions of Mn 4+ ions, respectively. 19,20 Notably, a substantial overlap between the broad blue absorption band and the emission region of InGaN blue chip were found, indicating that K 3 TaOF 6 :0.04Mn 4+ could be a promising candidate for LCD.…”

“…With the increasing of temperature, most electrons at 4 T 2g state will absorb the heat and climb to the crossover point of the 4 T 2g and 4 A 2g states once the accumulated energy exceeds DE a . Then, these electrons will return to the ground state 4 A 2g by a non-radiative way and give rise to thermal quenching, as demonstrated in congurational coordinate diagram (Fig. 4(c))…”

“…With the development of lighting and display technology in the past decades, there is an increasing requirement of the color quality of white lighting-emitting diode (w-LED) illuminant sources. [1][2][3][4][5] However, the commercially available w-LED devices, i.e., based on Y 3 Al 5 O 12 :Ce 3+ (YAG) yellow phosphors with InGaN blue chips are unsuitable for liquid crystal display (LCD) backlights due to their limited color gamut. [6][7][8] As an alternative, combining commercial CaAlSiN 3 :Eu 2+ red phosphors with bsialon:Eu 2+ green phosphors has been a popular model in the LCD backlight market.…”