论文标题
氧气缺乏α-MOO3，促进了H2O的吸附和气体传感器的状态猝灭：DFT研究
Oxygen Deficient α-MoO3 with Promoted Adsorption and State-Quenching of H2O for Gas Sensor: A DFT Study
论文作者
论文摘要
具有还原阳离子的半导体氧化物是纳米电子和催化剂中各种功能应用的理想平台。在这里，我们报告了一个超薄单层α-moo3，在引入氧气空位（VO）后，可调电子性能和不同的气体吸附行为。 Alpha-Moo3的独特特性是，它包含三种不同类型的氧原子，占据了三个Wyckoff位点，这些原子在其他低维氧化物中不存在，并提供了丰富的电子杂交状态。在间隙低于传导带〜0.59 eV的间隙中，VO触发中间状态的存在，并大大降低了工作函数，以及近乎红外线的新激发。与悬空状态相关的重新调整的费米水平降低了相邻的mo原子，并在此后影响气体吸附。与完美的晶格位点相比，VO上方的H2O分子的结合能为2.5倍，高达-0.75 eV，电子的传递趋势也逆转。后者与在完美MOO3上方吸附的H2O吸附的浅间隙中的浅层局部状态有关，后者在VO地点吸附时被淬灭。那些在缺氧缺氧中富裕的缺陷状态，拓宽了光吸收并促进水的吸收，是将α-MOO3用于光电子，光热疗法和水分传感器的应用。
Semiconducting oxides with reducible cations are ideal platforms for various functional applications in nanoelectronics and catalysts. Here we report an ultrathin monolayer alpha-MoO3 where tunable electronic properties and different gas adsorbing behaviors upon introducing the oxygen vacancies (VO). The unique property of alpha-MoO3 is that it contains three different types of oxygen atoms occupying three Wyckoff sites that are absent in other low-dimensional oxides and provides rich electronic hybridized states. The presence of VO triggers intermediate state in the gap at ~0.59 eV below the conduction band minimum and reduces the work function dramatically, together with new excitations at near infrared. The realigned Fermi level associated with the dangling state of VO reduces the neighboring Mo atoms and affects the gas adsorption thereafter. The binding energy of H2O molecules above VO is 2.5 times up to -0.75 eV compared with that of perfect lattice site and trends of transfer of electrons also reverse. The latter is related with the shallow localized state in the band gap due to H2O adsorbed above perfect MoO3 which becomes quenched upon adsorbing at the VO site. Those rich in-gap defective states in oxygen deficient MoO3, broadening the light absorption and promoting the uptake of water, are conductive to the application of alpha-MoO3 for optoelectronics, photothermal therapy, and sensor of moisture.
