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Báo cáo hóa học: " Kinetics of Si and Ge nanowires growth through electron beam evaporation"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Kinetics of Si and Ge nanowires growth through electron beam evaporation | Artoni et al. Nanoscale Research Letters 2011 6 162 http www.nanoscalereslett.eom content 6 1 162 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Kinetics of Si and Ge nanowires growth through electron beam evaporation Pietro Artoni1 2 Emanuele Francesco Pecora1 2 3 Alessia Irrera1 Francesco Priolo1 2 Abstract Si and Ge have the same crystalline structure and although Si-Au and Ge-Au binary alloys are thermodynamically similar same phase diagram with the eutectic temperature of about 360 C in this study it is proved that Si and Ge nanowires NWs growth by electron beam evaporation occurs in very different temperature ranges and fluence regimes. In particular it is demonstrated that Ge growth occurs just above the eutectic temperature while Si NWs growth occurs at temperature higher than the eutectic temperature at about 450 C. Moreover Si NWs growth requires a higher evaporated fluence before the NWs become to be visible. These differences arise in the different kinetics behaviors of these systems. The authors investigate the microscopic growth mechanisms elucidating the contribution of the adatoms diffusion as a function of the evaporated atoms direct impingement demonstrating that adatoms play a key role in physical vapor deposition PVD NWs growth. The concept of incubation fluence which is necessary for an interpretation of NWs growth in PVD growth conditions is highlighted. Introduction The synthesis and the tailoring of the electrical and optical properties of nanostructured materials are fascinating research fields and they represent a suitable route in a wide range of potential nanoscale device applications. Among these axial structures such as C nanotubes and group IV semiconductor nanowires NWs are a realistic addition because of the quantum confinement of their carriers in the planar direction and because of their high surface volume ratio. In the literature many simple device structures have been demonstrated taking advantage