| 1. |
- Huang, Xing, et al.
(författare)
-
Semiconducting Conjugated Coordination Polymer with High Charge Mobility Enabled by "4+2" Phenyl Ligands
- 2023
-
Ingår i: Journal of the American Chemical Society. - : AMER CHEMICAL SOC. - 0002-7863 .- 1520-5126. ; 145:4, s. 2430-2438
-
Tidskriftsartikel (refereegranskat)abstract
- Electrically conductive coordination polymers and metal-organic frameworks are attractive emerging electroactive materials for (opto-)electronics. However, developing semiconducting coordination polymers with high charge carrier mobility for devices remains a major challenge, urgently requiring the rational design of ligands and topological networks with desired electronic structures. Herein, we demonstrate a strategy for synthesizing high-mobility semiconducting conjugated coordination polymers (c-CPs) utilizing novel conjugated ligands with D2h symmetry, namely, "4 + 2" phenyl ligands. Compared with the conventional phenyl ligands with C6h symmetry, the reduced symmetry of the "4 + 2" ligands leads to anisotropic coordination in the formation of c-CPs. Consequently, we successfully achieve a single-crystalline three-dimensional (3D) c-CP Cu4DHTTB (DHTTB = 2,5-dihydroxy-1,3,4,6-tetrathiolbenzene), containing orthogonal ribbon-like pi-d conjugated chains rather than 2D conjugated layers. DFT calculation suggests that the resulting Cu4DHTTB exhibits a small band gap (similar to 0.2 eV), strongly dispersive energy bands near the Fermi level with a low electron-hole reduced effective mass (similar to 0.2m0*). Furthermore, the four-probe method reveals a semiconducting behavior with a decent conductivity of 0.2 S/cm. Thermopower measurement suggests that it is a p-type semiconductor. Ultrafast terahertz photoconductivity measurements confirm Cu4DHTTB's semiconducting nature and demonstrate the Drude-type transport with high charge carrier mobilities up to 88 +/- 15 cm2 V-1 s-1, outperforming the conductive 3D coordination polymers reported till date. This molecular design strategy for constructing high-mobility semiconducting c-CPs lays the foundation for achieving high-performance c-CP-based (opto-)electronics.
|
|
| 2. |
- Lu, Yang, et al.
(författare)
-
Precise tuning of interlayer electronic coupling in layered conductive metal-organic frameworks
- 2022
-
Ingår i: Nature Communications. - : Nature Portfolio. - 2041-1723. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Layered metal-organic frameworks attract interests for optoelectronics and spintronics. Here, the authors report a strategy to tune interlayer charge transport and thermoelectric properties via side-chain induced control of the layer spacing. Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) have attracted increasing interests for (opto)-electronics and spintronics. They generally consist of van der Waals stacked layers and exhibit layer-depended electronic properties. While considerable efforts have been made to regulate the charge transport within a layer, precise control of electronic coupling between layers has not yet been achieved. Herein, we report a strategy to precisely tune interlayer charge transport in 2D c-MOFs via side-chain induced control of the layer spacing. We design hexaiminotriindole ligands allowing programmed functionalization with tailored alkyl chains (HATI_CX, X = 1,3,4; X refers to the carbon numbers of the alkyl chains) for the synthesis of semiconducting Ni-3(HATI_CX)(2). The layer spacing of these MOFs can be precisely varied from 3.40 to 3.70 angstrom, leading to widened band gap, suppressed carrier mobilities, and significant improvement of the Seebeck coefficient. With this demonstration, we further achieve a record-high thermoelectric power factor of 68 +/- 3 nW m(-1) K-2 in Ni-3(HATI_C3)(2), superior to the reported holes-dominated MOFs.
|
|
| 3. |
- Lu, Yang, et al.
(författare)
-
sp-Carbon Incorporated Conductive Metal-Organic Framework as Photocathode for Photoelectrochemical Hydrogen Generation
- 2022
-
Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 61:39
-
Tidskriftsartikel (refereegranskat)abstract
- Metal-organic frameworks (MOFs) have attracted increasing interest for broad applications in catalysis and gas separation due to their high porosity. However, the insulating feature and the limited active sites hindered MOFs as photocathode active materials for application in photoelectrocatalytic hydrogen generation. Herein, we develop a layered conductive two-dimensional conjugated MOF (2D c-MOF) comprising sp-carbon active sites based on arylene-ethynylene macrocycle ligand via CuO4 linking, named as Cu3HHAE2. This sp-carbon 2D c-MOF displays apparent semiconducting behavior and broad light absorption till the near-infrared band (1600 nm). Due to the abundant acetylene units, the Cu3HHAE2 could act as the first case of MOF photocathode for photoelectrochemical (PEC) hydrogen generation and presents a record hydrogen-evolution photocurrent density of ≈260 μA cm−2 at 0 V vs. reversible hydrogen electrode among the structurally-defined cocatalyst-free organic photocathodes.
|
|
