用热灯丝辅助化学汽相沉积法在钼基板上沉积金刚石薄膜的研究

用热灯丝铺助化学汽相沉积(HFACVD)法,以H_2十CH_4为原料在钼基板上沉积出了金刚石膜。用扫描电镜,X射线衍射,激光Raman光谱和光荧光谱对所得金刚石膜进行了分析。实验结果表明,钼基板表面先生成了1层Mo_2C,然后,金刚石再在此Mo_2C上形核生长。所沉积的金刚石膜中仍含有一定的SP^2态碳和中性空缺等缺陷。

The effect of the substrate on the Raman and photoluminescence emission of single-layer MoS2

We quantitatively study the Raman and photoluminescence （PL） emission from single-layer molybdenum disulfide （MoS2） on dielectric （SiO2, hexagonal boron nitride, mica and the polymeric dielectric Gel-Film） and conducting substrates （Au and few-layer graphene）. We find that the substrate can affect the Raman and PL emission in a twofold manner. First, the absorption and emission intensities are strongly modulated by the constructive/destructive interference within the different substrates. Second, the position of the Alg Raman mode peak and the spectral weight between neutral and charged excitons in the PL spectra are modified by the substrate. We attribute this effect to substrate-induced changes in the doping level and in the decay rates of the excitonic transitions. Our results provide a method to quantitatively study the Raman and PL emission from MoSa-based vertical heterostructures and represent the first step in ad hoc tuning the PL emission of 1L MoS2 by selecting the proper substrate.