Journal: Nano-Micro Letters

Article Title: A Universal Atomic Substitution Conversion Strategy Towards Synthesis of Large-Size Ultrathin Nonlayered Two-Dimensional Materials

doi: 10.1007/s40820-021-00692-6

Figure Lengend Snippet: Growth and characterization of layered CdI 2 flakes. a Schematic drawing of HPVVD setup for growth of CdI 2 flakes on mica substrate. b The typical OM image of large-area CdI 2 flakes grown on mica substrate showing both triangular and hexagonal geometry. c Representative OM image of a large-size CdI 2 flake with hexagonal shape on mica substrate. d AFM image and corresponding height profile of a typical monolayer CdI 2 . e Raman spectrum of CdI 2 flakes. The inset is the typical OM and Raman intensity mapping (E g and A 1g mode) of a triangular CdI 2 flake. f XRD pattern of CdI 2 flakes grown on SiO 2 /Si substrate. g HRTEM image of CdI 2 flakes. The inset is the SAED pattern taken along the direction [001] of CdI 2 flakes. h , i XPS spectra of Cd 3d and I 3d peaks from CdI 2 flakes

Article Snippet: The crystal structure, phase, and composition were analyzed using X-ray powder diffraction (XRD) (Bruker, D2 phaser), X-ray photoelectron spectroscopy (XPS) (Kratos, AXIS-ULTRA DLD-600 W), microscope-based Raman spectrometer (WITec, Alpha 300RS+, 532 nm excitation laser) equipped with a 100X objective lens, and transmission electron microscopy (TEM) (FEI, Tecnai G2 F30) equipped with an energy-dispersive X-ray spectroscopy (EDS) system.

Techniques:

Journal: Nano-Micro Letters

Article Title: A Universal Atomic Substitution Conversion Strategy Towards Synthesis of Large-Size Ultrathin Nonlayered Two-Dimensional Materials

doi: 10.1007/s40820-021-00692-6

Figure Lengend Snippet: Growth and characterization of nonlayered CdS flakes. a Schematic presentation of conversion setup and atomic structure of CdS flakes on mica substrate by chemical sulfurization method. b , c Representative OM images of original large-scale CdI 2 thin flake and converted CdS thin flake on mica substrates, respectively. d AFM image and corresponding height profile of thin CdS flake in panel c. e Raman spectrum of converted CdS flakes. The inset is the typical OM and Raman intensity mapping (1LO mode) of the triangular CdS flake. f XRD pattern of converted CdS flakes on SiO 2 /Si substrate. g HRTEM image of converted CdS flakes. The inset is the SAED pattern taken along the direction [001] of CdS flakes. h , i XPS spectra of Cd 3d and S 2p peaks from converted CdS flakes

Article Snippet: The crystal structure, phase, and composition were analyzed using X-ray powder diffraction (XRD) (Bruker, D2 phaser), X-ray photoelectron spectroscopy (XPS) (Kratos, AXIS-ULTRA DLD-600 W), microscope-based Raman spectrometer (WITec, Alpha 300RS+, 532 nm excitation laser) equipped with a 100X objective lens, and transmission electron microscopy (TEM) (FEI, Tecnai G2 F30) equipped with an energy-dispersive X-ray spectroscopy (EDS) system.

Techniques:

Journal: Nano-Micro Letters

Article Title: A Universal Atomic Substitution Conversion Strategy Towards Synthesis of Large-Size Ultrathin Nonlayered Two-Dimensional Materials

doi: 10.1007/s40820-021-00692-6

Figure Lengend Snippet: The controllable sulfidation of CdI 2 flakes and corresponding conversion mechanism of CdS flakes. a The thickness of CdI 2 flakes before (AFM images above data line) and after being converted to CdS flakes (AFM images below data line). Inset: the representative AFM images and corresponding Raman intensity mapping of CdI 2 flakes and converted CdS flakes. Note that the thickness of the CdI 2 flakes was about 1.95 times higher compared to the corresponding of CdS flakes, which agrees well with the ratio of the c lattice constant between the two compounds. b , c The theory calculations and the proposed growth mechanism of CdS flakes. b Left: the calculated Gibbs free energy changes versus the temperature for the chemical reaction concerning the conversion process. Right: the calculated formation enthalpy changes versus the temperature for CdI 2 and CdS. c The DFT-calculated energy profile of the possible reaction pathway for CdS

Article Snippet: The crystal structure, phase, and composition were analyzed using X-ray powder diffraction (XRD) (Bruker, D2 phaser), X-ray photoelectron spectroscopy (XPS) (Kratos, AXIS-ULTRA DLD-600 W), microscope-based Raman spectrometer (WITec, Alpha 300RS+, 532 nm excitation laser) equipped with a 100X objective lens, and transmission electron microscopy (TEM) (FEI, Tecnai G2 F30) equipped with an energy-dispersive X-ray spectroscopy (EDS) system.

Techniques: