Ball Biswajit, Chakravarty Chandrima, Mandal Bikash, Sarkar Pranab
Department of Chemistry, Visva-Bharati University, Santiniketan 731235, India.
ACS Omega. 2019 Feb 18;4(2):3556-3564. doi: 10.1021/acsomega.8b03488. eCollection 2019 Feb 28.
Using the state-of-the-art theoretical method, we have investigated the electronic and optical properties of a thiophene-based covalent triazine framework (TBCTF). We have found that TBCTF is a direct band gap semiconductor. Our calculations reveal that constitutional isomerism is a tool for band gap tuning. The variation of band gap can be achieved by the bilayer TBCTF formation and further can be tuned by the -axial strain. We have designed a new two-dimensional van der Waals heterostructure g-ZnO/TBCTF, which shows type-II band alignment, ensuring effective separation of photogenerated electron-hole pairs. This composite system also exhibits enhanced absorption in the visible range compared to that of individual g-ZnO and TBCTF monolayers. Therefore, this composite system may find potential application in photovoltaic devices. We have also investigated the hydrogen adsorption ability of TBCTF through Li atom doping. Our results indicate that the calculated hydrogen adsorption energies lie in the range, which is suitable for reversible hydrogen storage under ambient conditions. Therefore, the lithium-doped TBCTF may be a potential candidate for the hydrogen storage material.
利用最先进的理论方法，我们研究了基于噻吩的共价三嗪框架（TBCTF）的电子和光学性质。我们发现TBCTF是一种直接带隙半导体。我们的计算表明，构造异构是一种调节带隙的工具。通过形成双层TBCTF可以实现带隙的变化，并且进一步可以通过轴向应变进行调节。我们设计了一种新型二维范德华异质结构g-ZnO/TBCTF，它显示出II型能带排列，确保光生电子-空穴对的有效分离。与单独的g-ZnO和TBCTF单层相比，这种复合系统在可见光范围内也表现出增强的吸收。因此，这种复合系统可能在光伏器件中找到潜在应用。我们还通过锂原子掺杂研究了TBCTF的氢吸附能力。我们的结果表明，计算得到的氢吸附能在该范围内，这适用于在环境条件下的可逆氢存储。因此，锂掺杂的TBCTF可能是氢存储材料的潜在候选者。
