Hafnium Disulfide Powder
|Molecular weight||242.62 g/mol|
|Bandgap||~ 2.0 eV (indirect); ~ 1.2 eV (direct)|
|Classification / Family||Transition metal dichalcogenides (TMDCs), 2D Semiconductor materials, Nano-electronics, Nano-photonics, Photovoltaic, Materials science|
|Preparation||Synthetic - chemical vapour transport (CVT)|
|Electronic properties||2D semiconductor|
|Appearance||Dark brown powder|
Like all other 2D materials (such as graphite), Hafnium disulfide (HfS2) powder has a layered structure. Each layer is bound by weak van der Waals forces. Ultra-thin films of HfS2 can be chemically-exfoliated from its layered bulk powder form. HfS2 crystallises with octahedral metal coordination in the 1T polytype.
1T-HfS2 is semiconducting in nature. Ultrathin HfS2 shows a higher, faster response and higher stability than most other two-dimensional materials. However, the 1T-HfS2 monolayer system undergoes a semiconductor-to-metal transition while compressive strain is applied.
Exfoliated ultra-thin films of HfS2 have an indirect bandgap of ~ 1.2 eV, with high stability against surface degradation. FET based on HfS2 nanosheets gave a high current on/off ratio over 10,000 at room temperature. Photodetectors based on HfS2 nanosheets provide high photosensitivity to 405 nm lasers, with a large on/off ratio of ca. 103 and ultrafast response performance (with rise and fall times of 24 ms).
2D-HfS2 can also be used as an efficient photocatalyst for water splitting, with a strong absorption mainly in the visible and ultraviolet regions.
Hafnium disulfide powder is obtained via the CVT method, with a purity in excess of 99.995% achieved.
Hafnium disulfide powder is suitable for liquid chemical exfoliation to prepare HfS2 nanosheets and nanoparticles down to few-layer films. HfS2 powder is also used to prepare mono-layer and few-layer films via chemical vapour deposition (CVD).
Literature and Reviews
- High-yield synthesis and liquid-exfoliation of twodimensional belt-like hafnium disulphide, H. Kaur et al., Nano Res., 11(1): 343–353 (2018); doi: 10.1007/s12274-017-163.
- Vertically oriented few-layered HfS2 nanosheets: growth mechanism and optical properties, B. Zheng et al., 2D Mater., 3, 035024 (2016); doi:10.1088/2053-1583/3/3/035024.
- Efficient charge separation and visible-light response in bilayer HfS2-based van der Waals heterostructures, B. Wang et al., RSC Adv., 8, 18889 (2018); DOI: 10.1039/c8ra03047b.
- Few-layer HfS2 transistors, T. Kanazawa et al., Sci. Rep., 6, 22277 (2015); DOI: 10.1038/srep22277.
- Ultrasensitive Phototransistors Based on Few-Layered HfS2, K. Xu et al., Adv. Mater., 27, 7881–7887 (2015); DOI: 10.1002/adma.201503864.
- Toward High-Performance Top-Gate Ultrathin HfS2 Field-Effect Transistors by Interface Engineering, K. Xu et al., small, 12 (23), 3106–3111 (2016); DOI: 10.1002/smll.201600521.
- Space-Confined Chemical Vapor Deposition Synthesis of Ultrathin HfS2 Flakes for Optoelectronic Application, C. Yan et al., Adv. Funct. Mater., 27, 1702918 (2017); DOI: 10.1002/adfm.201702918.
To the best of our knowledge the technical information provided here is accurate. However, Ossila assume no liability for the accuracy of this information. The values provided here are typical at the time of manufacture and may vary over time and from batch to batch.