Piazza Aurora, Giannazzo Filippo, Buscarino Gianpiero, Fisichella Gabriele, Magna Antonino La, Roccaforte Fabrizio, Cannas Marco, Gelardi Franco Mario, Agnello Simonpietro
CNR-IMM, Strada VIII, 5, Zona Industriale, 95123 Catania, Italy; Department of Physics and Chemistry, University of Palermo, Via Archirafi 36 - Palermo, 90123, Italy; Department of Physics and Astronomy, University of Catania, Via Santa Sofia 64 - Catania, 95123, Italy.
CNR-IMM, Strada VIII, 5, Zona Industriale, 95123 Catania, Italy.
Beilstein J Nanotechnol. 2017 Feb 10;8:418-424. doi: 10.3762/bjnano.8.44. eCollection 2017.
The effects of temperature and atmosphere (air and O) on the doping of monolayers of graphene (Gr) on SiO and Si substrates, and on the doping of MoS multilayer flakes transferred on the same substrates have been investigated. The investigations were carried out by in situ micro-Raman spectroscopy during thermal treatments up to 430 °C, and by atomic force microscopy (AFM). The spectral positions of the G and 2D Raman bands of Gr undergo only minor changes during treatment, while their amplitude and full width at half maximum (FWHM) vary as a function of the temperature and the used atmosphere. The thermal treatments in oxygen atmosphere show, in addition to a thermal effect, an effect attributable to a p-type doping through oxygen. The thermal broadening of the line shape, found during thermal treatments by in situ Raman measurements, can be related to thermal phonon effects. The absence of a band shift results from the balance between a red shift due to thermal effects and a blue shift induced by doping. This shows the potential of in situ measurements to follow the doping kinetics. The treatment of MoS in O has evidenced a progressive erosion of the flakes without relevant spectral changes in their central zone during in situ measurements. The formation of MoO on the edges of the flakes is observed indicative of the oxygen-activated transformation.
研究了温度和气氛（空气和氧气）对二氧化硅（SiO）和硅（Si）衬底上石墨烯（Gr）单层的掺杂以及对转移到相同衬底上的二硫化钼（MoS）多层薄片的掺杂的影响。通过在高达430°C的热处理过程中进行原位显微拉曼光谱以及原子力显微镜（AFM）进行了这些研究。Gr的G和2D拉曼带的光谱位置在处理过程中仅发生微小变化，而它们的幅度和半高宽（FWHM）则随温度和所用气氛而变化。在氧气气氛中的热处理除了显示出热效应外，还显示出通过氧进行p型掺杂的效应。通过原位拉曼测量在热处理过程中发现的线形热展宽可能与热声子效应有关。由于热效应引起的红移和掺杂引起的蓝移之间的平衡导致没有带移。这显示了原位测量跟踪掺杂动力学的潜力。在原位测量过程中，MoS在氧气中的处理证明了薄片的逐渐侵蚀，而其中心区域没有相关的光谱变化。观察到薄片边缘形成MoO，表明发生了氧活化转变。
