| Autor: |
Morris, Collin D., Qian, Eric K., Meza, Patricia E., Sangwan, Vinod K., Malliakas, Christos D., Hersam, Mark C., Kanatzidis, Mercouri G. |
| Zdroj: |
Inorganic Chemistry; 20240101, Issue: Preprints |
| Abstrakt: |
Single-wall nanotubes of isostructural AsPS4–xSex(x= 0, 1) are grown from solid-state reaction of stoichiometric amounts of the elements. The structure of AsPS4was determined using single-crystal X-ray diffraction and refined in space group P1¯. The infinite, single-walled AsPS4nanotubes have an outer diameter of ≈1.1 nm and are built of corner-sharing PS4tetrahedra and AsS3trigonal pyramids. Each nanotube is nearly hexagonal, but the ≈3.4 Å distance between S atoms on adjacent nanotubes allows them to easily slide past one another, resulting in the loss of long-range order. Substituting S with Se disrupted the crystallization of the nanotubes, resulting in amorphous products that precluded the determination of the structure for AsPS3Se. 31P solid-state NMR spectroscopy indicated a single unique tetrahedral P environment in AsPS4and five different P environments all with different degrees of Se substitution in AsPS3Se. Optical absorption spectroscopy revealed an energy band gap of 2.7 to 2.4 eV for AsPS4and AsPS3Se, respectively. Individual AsPS4microfibers showed a bulk conductivity of 3.2 × 10–6S/cm and a negative photoconductivity effect under the illumination of light (3.06 eV) in ambient conditions. Thus, intrinsic conductivity originates from hopping through empty trap states along the length of the AsPS4nanotubes. |
| Databáze: |
Supplemental Index |
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