论文标题
$ srtao_2n/h_2o $接口变化的晶格常数和第一原理计算的表面终止的频段对齐研究
Band alignment study at the $SrTaO_2N/H_2O$ interface varying lattice constants and surface termination from first-principles calculations
论文作者
论文摘要
在寻找新的可再生能源以替代化石燃料，氢是清洁能源生产的最有前途的候选者之一。但是廉价的氢分离和存储仍然是一个巨大的挑战。光电化学设备对于将水分子分解为$ 2H_2+O_2 $看起来很有希望。每天都会发现或发明新材料和组合，以提高复杂总过程的效率。光电化学过程在没有偏置电压的情况下工作的必要条件是，半导体传导带（CBM）的最低限度必须比还原潜在的$ h^{+} $比$ h_2 $更积极，而半导体价频段（VBM）的最高价值比$ o y_ $ o o o o o o o o o o y $ h___2。因此，在水的半导体界面中进行带对齐研究变得至关重要。在这项工作中，已经在$ srtao_2n/h_2o $ interfaces中进行了基于所有电子和伪电势方法中的密度功能理论（DFT）的第一原理计算。分析了不同的表面终止，以及差距和带状对齐与晶格常数的依赖性对不匹配的底物生长的系统的依赖性。水结构是根据经典分子动力学及其电子结构使用DFT构建的。该计算表明，$ srtao_2n $（001）适用于各种晶格常数A上的光电化学应用，但压缩/伸长率为-2％，-1％和3％，而STN（110）结果适用于适用于光线体范围的光层范围为-1％％的光电机设备，以下是-1％。
In the search for new renewable energy to replace fossil fuels, Hydrogen is one of the most promising candidates for clean energy production. But cheap Hydrogen separation and storage is still a big challenge. Photoelectrochemical devices look promising for the decomposition of the water molecule into $2H_2+O_2$. Every day new materials and combinations are discovered or invented to improve the efficiency of the complex total process. A necessary condition for the photoelectrochemical process to work without a bias voltage is that the minimum of the semiconductor conduction band (CBM) must be more positive than the reduction potential $H^{+}$ to $H_2$, whereas the highest value of the semiconductor valence band (VBM) must be more negative than the oxidation potential of $H_2O$ to $O_2$. Thus, band alignment studies in interfaces of semiconductors with water become of vital importance. In this work, first principles calculations based on density functional theory (DFT) in the all electron and the pseudo potential approaches have been performed for the analysis of the band alignment in $SrTaO_2N/H_2O$ interfaces. Different surface terminations were analyzed, together with the dependence of the gap and band alignment with lattice constants for systems grown on mismatched substrates. Water structures were built from classical molecular dynamics and its electronic structure calculated using DFT. The calculations show that the $SrTaO_2N$ (001) is suitable for photoelectrochemical applications on a wide range of lattice constant a, except for a compression/elongation of -2%, -1% and 3%, while STN (110) results suitable for photoelectrochemical devices over a wider range of lattice constants from -1% to 3%.
