Kaneko Yuta, Terada Kosuke, Teii Kungen
Department of Applied Science for Electronics and Materials, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan.
Nanotechnology. 2020 Apr 17;31(16):165203. doi: 10.1088/1361-6528/ab6748.
Metal nanoparticles are deposited on nitrogen-incorporated carbon nanowalls (CNWs) using Ag, Au, In, and Mg as metal species for enhancing field emission. Morphology, coverage, chemical composition, and crystallinity of the metal coatings on CNW surfaces are examined by varying nominal thickness of metals within 10 nm. The emission characteristics reveal that coating CNWs with any metal species lowers emission turn-on fields and thus increases emission efficiency. The inverse dependence of field enhancement factor and turn-on field upon nominal thickness of metals confirms that additional field amplification at metal nanoparticles governs emission efficiency regardless of work functions of the metals. The Ag-coated CNWs retain the highest current density for long-time emission at a constant applied field, while the non-coated CNWs have higher emission stability and a larger time constant of current degradation than the metal-coated ones.
使用银、金、铟和镁作为金属种类，将金属纳米颗粒沉积在掺氮碳纳米壁（CNWs）上，以增强场发射。通过改变金属标称厚度在10纳米以内，研究了CNW表面金属涂层的形貌、覆盖率、化学成分和结晶度。发射特性表明，用任何金属种类涂覆CNWs都会降低发射开启场，从而提高发射效率。场增强因子和开启场与金属标称厚度的反比关系证实，无论金属的功函数如何，金属纳米颗粒处的额外场放大决定了发射效率。在恒定施加场下，涂银的CNWs在长时间发射时保持最高电流密度，而未涂覆的CNWs比涂覆金属的CNWs具有更高的发射稳定性和更大的电流衰减时间常数。
