By incorporating ultrathin (<0.1 nm) green, yellow, and red phosphorescence layers with different sequence arrangements in a blue fluorescence layer, four unique and simplified fluorescence/phosphorescence (F/P) hybrid, white organic light-emitting diodes (WOLEDs) were obtained. All four devices realize good warm white light emission, with high color rending index (CRI) of >80, low correlated color temperature of <3600 K, and high color stability at a wide voltage range of 5 V-9 V. These hybrid WOLEDs also reveal high forward-viewing external quantum efficiencies (EQE) of 17.82%-19.34%, which are close to the theoretical value of 20%, indicating an almost complete exciton harvesting. In addition, the electroluminescence spectra of the hybrid WOLEDs can be easily improved by only changing the incorporating sequence of the ultrathin phosphorescence layers without device efficiency loss. For example, the hybrid WOLED with an incorporation sequence of ultrathin red/yellow/ green phosphorescence layers exhibits an ultra-high CRI of 96 and a high EQE of 19.34%. To the best of our knowledge, this is the first WOLED with good tradeoff among device efficiency, CRI, and color stability. The introduction of ultrathin (<0.1 nm) phosphorescence layers can also greatly reduce the consumption of phosphorescent emitters as well as simplify device structures and fabrication process, thus leading to low cost. Such a finding is very meaningful for the potential commercialization of hybrid WOLEDs.

coupling effect induced by heavy-metal atoms. [5,6] For example, noble metal-based phosphors including iridium(III) complexes, [7][8][9][10][11][12][13][14][15][16] platinum(II) complexes, [17][18][19][20] and gold(III) complexes [21,22] have been widely used in phosphorescent OLEDs (PhOLEDs). However, these noble metals suffer from the low abundance and high cost. Hence, the relatively abundant, lowcost, and low-toxic phosphorescent metal complex have been drawing great interests for PhOLEDs.Recent explorations of phosphorescent manganese(II) complexes appear to be a new and attractive alternative toward highly efficient PhOLEDs. The manganese(II) complexes display strong photoluminescence in solid state originating from the metal-centered d-d ( 4 T 1 (G) → 6 A 1 ) radiative transition. [23][24][25] The well-known green light-emitting manganese(II) complexes are ionic compounds consisting of organic cations and inorganic tetrahalogenomanganate(II) anions. [26,27] Attributed to their excellent solid-state photophysical properties, this kind of organic-inorganic hybrid complexes have exhibited promising optoelectronic applications. For example, Chen and co-workers have realized the solution-processed PhOLEDs based on the ionic tetrabromide manganese(II) complex ((Ph 4 P) 2 (MnBr 4 )) as an emitting dopant, the external quantum efficiency (EQE) of this device can reach 9.6% for the doped OLEDs. [28] However, the ionic manganese(II) complexes often suffer from low stability and can be easily hydrolyzed Phosphorescent transition-metal complexes have played the vital role in the rapid development of organic light-emitting diodes (OLEDs) as the most promising candidates for next-generation flat-panel display and solid-state lighting techniques. In this work, novel and low-cost phosphorescent neutral tetrahedral manganese(II) complexes (DBFDPO-MnX 2 , X = Br, or Cl) based on dibenzofuran-based phosphine oxide derivative as ligand are designed and synthesized. The manganese(II) complexes exhibit intense green phosphorescence with high photoluminescence quantum yields (PLQYs) of as high as 81.4% (DBFDPO-MnBr 2 ). Using complex DBFDPO-MnBr 2 as dopant, a green OLED with current efficiency (CE max ) of 35.47 cd A −1 , power efficiency (PE max ) of 34.35 lm W −1 , and external quantum efficiency (EQE max ) of 10.49% is fabricated. Interestingly, red exciplex emission is also observed in electroluminescence, arising from the interaction between the host materials (bis(2-(2-hydroxyphenyl)-pyridine)beryllium (Bepp 2 ) or 1,3,5-tris(2-N-phenylbenzimidazolyl)benzene (TPBi)) and the dopant (DBFDPO-MnBr 2 ).The exciplex-based red OLED in this study exhibits the maximum CE and PE reaching 18.64 cd A −1 and 17.92 lm W −1 , respectively, which are among the up-to-date highest values for exciplex-based red OLEDs. Beneficial from the exciplex, it has the great potential to broaden the electroluminescent spectra with manganese(II) complex. Phosphorescent OLEDsThe ORCID identification number(s) for the author(s) of this article can be fou...

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Coping with the shortage of fresh water and electricity in off-grid and resource-constrained areas through sustainable strategies has become the most urgent challenge facing the development of human society. Herein, we propose a low-cost and sustainable way of repurposing discarded pomelo peel by converting it into 3D porous carbon foam (i.e., carbonized pomelo peel, referred to as CPP) with multichannel waterways for synergetic coupling of solar-driven interfacial evaporation (SDIE) and low-grade heat-to-electricity generation. The superhydrophilic 3D porous CPP with multichannel waterways utilizes its powerful water supply capability to avoid salt accumulation during continuous seawater desalination. By cautiously weighing the water transport and thermal management of CPP-based evaporators, CPP with three-channel waterways (CPP3) can achieve efficient solar-driven evaporation (the evaporation rate of 1.37 kg m −2 h −1 , one sun) on the premise of salt resistance through its superior light absorption and ultrafast solar-thermal response. Besides, a collaborative device integrating CPP3 and a commercial thermoelectric (TE) generator is designed for synchronous generation of solar steam and thermoelectricity, which can simultaneously achieve an evaporation rate of 1.39 kg m −2 h −1 and a power output of 0.5 W m −2 under one sun illumination. Such a cost-effective and easy-to-manufacture strategy can provide potential opportunities for satisfying the demand for fresh water and electricity in resource-constrained areas.

Two highly efficient red neutral iridium(III) complexes, Ir1 and Ir2, were rationally designed and synthesized by selecting two pyridylimidazole derivatives as the ancillary ligands. Both Ir1 and Ir2 show nearly the same photoluminescence emission with the maximum peak at 595 nm (shoulder band at about 638 nm) and achieve high solution quantum yields of up to 0.47 for Ir1 and 0.57 for Ir2. Employing Ir1 and Ir2 as emitters, the fabricated red organic light-emitting diodes (OLEDs) show outstanding performance with the maximum external quantum efficiency (EQE), current efficiency (CE), and power efficiency (PE) of 20.98%, 33.04 cd/A, and 33.08 lm/W for the Ir1-based device and 22.15%, 36.89 cd/A, and 35.85 lm/W for the Ir2-based device, respectively. Furthermore, using Ir2 as red emitter, a trichromatic hybrid white OLED, showing good warm white emission with low correlated color temperature of <2200 K under the voltage of 4-6 V, was fabricated successfully. The white device also realizes excellent device efficiencies with the maximum EQE, CE, and PE reaching 22.74%, 44.77 cd/A, and 46.89 lm/W, respectively. Such high electroluminescence performance for red and white OLEDs indicates that Ir1 and Ir2 as efficient red phosphors have great potential for future OLED displays and lightings applications.

The OLEDs, having mixed hosts sandwiched between hole- and electron-transporting hosts, exhibit an EQE exceeding the theoretical limit and extremely small efficiency roll-off.

Achieving high efficiency and stable pure blue colloidal perovskite quantum dot (QD) light-emitting diodes (LEDs) is still an enormous challenge because blue emitters typically exhibit high defect density, low photoluminescence quantum yield (PLQY) and easy phase dissociation. Herein, an organic cation composition modification strategy is used to synthesize high-performance pure blue perovskite quantum dots at room temperature. The synthesized FA-CsPb(Cl0.5Br0.5)3 QDs show a bright photoluminescence with a high PLQY (65%), which is 6 times higher than the undoped samples. In addition, the photophysical properties of the FA cation doping was deeply illustrated through carrier dynamics and first principal calculation, which show lower defects, longer lifetime, and more reasonable band gap structure than undoped emitters. Consequently, pure blue FA-CsPb(Cl0.5Br0.5)3 QDs light-emitting devices were fabricated and presented a maximum luminance of 1452 cd m−2, and an external quantum efficiency of 5.01 % with an emission at 474 nm. The excellent photoelectric properties mainly originate from the enhanced blue QDs emitter and effective charge injection and exciton radiation. Our finding underscores this easy and feasible room temperature doping approach as an alternative strategy to blue perovskite QD LED development.

The microcarrier system offers an attractive method for cellular amplification and phenotype enhancement in the field of bone tissue engineering. However, it remains a challenge to fabricate porous microcarriers with osteoinductive activity for speedy and high-quality osseointegration in regeneration of serious complication of bone fracture, like nonunion. Here, we present a facile method for the first time manufacture microcarriers with osteogenic effects and properties based on well controlled and long-term Sr release. At first, strontium-substituted hydroxyapatite was prepared (Sr-HA) and a novel Sr-HA-graft-poly(γ-benzyl-l-glutamate) (Sr-HA-PBLG) nanocomposite was synthesized. Then, the microcarriers with highly interconnected macropores were fabricated by a double emulsion method, which allowed cells to adhere and proliferate and secrete extracellular matrix. Besides, the microcarriers with a relatively uniform diameter of 271.5 ± 45.0 μm are feasible for injection. The Sr-HA-PBLG microcarriers efficiently promoted osteogenic gene expression in vitro. With injection of the Sr-HA-PBLG microcarriers loading adipose derived stem cells (ADSCs) into the nonunion sites, bone regeneration was observed at 8 weeks after injection in a mice model.