A new type of blue-shifted aggregation-induced emission enhancement was observed for a Sn(
iv
) fluoride complex, resulting in strong emission in the solid state as compared with that in solutions. ...The fluorinated Sn(
iv
) complex has a significantly more intense emission efficiency compared to the chlorinated Sn(
iv
) complex, which is attributed to stronger σ bonding.
A fluorinated Sn(
iv
) complex not only significantly enhances the emission efficiency, but also exhibits blue-shifted aggregation-induced emission enhancement (AIEE) properties.
A unique type of inorganic−organic hybrid semiconductor bulk material is capable of emitting direct white light. Their photoluminescence properties can be tuned precisely and systematically by ...modifying structures and composition. They could be used as a single-material light-emitting source in high efficiency white-light-emitting diodes.
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Three new tin(IV) halide complexes with 5,7-dimethyl-8-quinolinol (dmqo), Sn(dmqo)
2
F
2
(1), Sn(dmqo)
2
Cl
2
(2a and 2 b), and Sn(dmqo)
2
I
2
(3), have been synthesized and characterized by ...single-crystal X-ray diffraction, UV-Vis spectroscopy, fluorescence, and thermal analysis. The three crystals are of the monoclinic system with space group P2
1
/c. A second polymorph of 2 was observed in the space group C2/c. The Sn(IV) center is six coordinate with two bidentate ligands with N and O donor atoms and two halides in a slightly distorted octahedral geometry. The tin(IV) complexes exhibit parallel displaced packing configuration between 5,7-dimethyl-8-quinolinol ligands. Increasing the size of the halide coordinated with the Sn(IV) center increases molecular packing distortion, resulting in weakening π-π interactions between pyridyl rings. Photoluminescence and thermal properties are affected by halide coordination with tin. The relative quantum yields of Sn(dmqo)
2
F
2
and Sn(dmqo)
2
Cl
2
are higher than that of Sn(dmqo)
2
I
2
. Complexes 1 and 2 show interesting blue-shifted emissions in the solid state compared to solution. Thermal stability decreases in the order of increasing the size of halide coordinated to Sn(IV).
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A new chemical route to Cu2ZnSn(SxSe1‐x)4 based thin film solar cells has been developed using spin coating of commercially available molecular precursors from an environmentally friendly non‐toxic ...solvent. 4.1% efficiency solar cells were achieved after selenization of Cu2ZnSnS4. This technique could provide simple, facile, and reproducible fabrication for efficient and large area solar cells.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Hybrid semiconductors of the general formula 2D-Cd sub(2)Se sub(2)(ba):Te (ba = bultylamine) emit direct white light upon illumination of UV-LED. The band gap and photoluminescence properties of this ...group of materials can be systematically tuned by changing the composition and doping level. The sample with 25 mol% of Te corresponds to the CIE coordinates of (0.29, 0.35), which is closest to the equi-energy white point (0.33, 0.33). These hybrid materials are also highly photoconductive with large gain under illumination of visible light.
A group of copper iodide-based hybrid semiconductors with the general formula of 2D-CuI(L)0.5 (L = organic ligands) are synthesized and structurally characterized. All compounds are two-dimensional ...(2D) networks made of one-dimensional (1D) copper iodide staircase chains that are interconnected by bidentate nitrogen-containing ligands. Results from optical absorption and emission experiments and density functional theory (DFT) calculations reveal that their photoluminescence (PL) can be systematically tuned by adjusting the lowest unoccupied molecular orbital (LUMO) energies of the organic ligands. Charge carrier transport measurements were carried out for the first time on single crystals of selected 2D-CuI(L)0.5 structures, and the results show that they possess p-type conductivity with a Hall mobility of ∼1 cm2 V–1 s–1 for 2D-CuI(pm)0.5 and 0.13 cm2 V–1 s–1 for 2D-CuI(pz)0.5, respectively. These values are comparable to or higher than the mobilities of typical highly luminescent organic semiconductors. This work suggests that robust, high-dimensional copper iodide hybrid semiconductors are promising candidates to be considered as a new type of emissive layer for light-emitting diode (LED) devices.
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Earth abundant absorber materials are the most promising candidates for terawatt-scale thin film photovoltaics due to the robust supply chains for the elements involved. The strongest initial ...candidate appears to be Cu 2 ZnSnS 4 (CZTS), but there are other potential material systems such as FeS 2 , CuO, and PbS that are just beginning to be re-examined with solution phase processing. Here we report a new, facile, and scalable chemical route to Earth abundant element thin film solar cells by coating a solution of highly soluble, inexpensive, and commercially available precursors in an environmentally friendly non-toxic solvent to form device quality films. Air-stable CZTS photovoltaic devices with 4.1% total area power conversion efficiency are obtained. We have generalized the chemical route and have used it to also fabricate PbS devices that are 1.5% efficient.
A unique family of II−VI based nanostructured inorganic−organic hybrid semiconductors exhibit nearly zero uniaxial thermal expansion in the temperature range of 95−295 K. Both their optoelectronic ...and thermal expansion properties are systematically tunable. The diamine molecules show a strong negative thermal expansion effect, and the extent of such an effect increases as the length of the organic molecules increases.
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Hybrid semiconductors of the general formula 2D-Cd
2
Se
2
(
ba
):Te (
ba
= bultylamine) emit direct white light upon illumination of UV-LED. The band gap and photoluminescence properties of this ...group of materials can be systematically tuned by changing the composition and doping level. The sample with 25 mol% of Te corresponds to the CIE coordinates of (0.29, 0.35), which is closest to the equi-energy white point (0.33, 0.33). These hybrid materials are also highly photoconductive with large gain under illumination of visible light.
Double-layer Te substituted 2D-Cd
2
Se
2
(
ba
) hybrid semiconductors emit direct white light upon illumination of UV-LED.
We have developed and studied selected properties of a novel type of inorganicorganic hybrid semiconductor materials in order to enhance the functionality over their parent structures. Since these ...hybrid semiconductor materials are composed of both inorganic and organic segments, one may expect them to have the advantage of combining the excellent electrical, optical, thermal and transport properties from the inorganic component with the flexibility, processability and structural diversity from the organic component. As a continuing effort, we have synthesized, modified, and characterized a number of selected structures with potential for solid state lighting applications. For example, we have developed the first inorganic-organic semiconductor bulk material, double-layered 2D-Cd2Q2(ba) (Q = S, Se), capable of producing direct white light. This type of materials could be promising for use as a single-material white-light-emitting source in white LEDs. Luminescence properties of these hybrid semiconductors can be tuned systematically by changing their composition and doping level. In addition, a thin pellet of one of our hybrid semiconductor materials without any modifications showed low electrical conductivity. Significant improvement may be anticipated with compositional and structural modifications on this system. Solution processed deposition techniques provide great opportunities for optical and optoelectronic devices, such as displays, solid state lighting, and solar cells, because it enables to fabricate flexible devices with low-cost and large area fabrications. Most semiconductors show very low solubility in organic solvents, thus limiting the opportunities to prepare thin films using soluble precursors. In this study, we have developed a simple, efficient, and low-cost solution-processed deposition route to fabricate metal chalcogenide semiconductor thin films by using soluble precursors via spin-coating techniques. Surface morphology was directly influenced by the choice of organic solvents as well as the spin-coating sequences, thus affecting the electrical transport of the films. In the case of hybrid semiconductors, a conducting polymer was employed to help forming more uniform composite films.
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