The influences of the plasma ignition condition in plasma enhanced chemical vapour deposition （PECVD） on the interfaces and the microstructures of hydrogenated microcrystalline Si （μc-Si：H） thin films are invest...The influences of the plasma ignition condition in plasma enhanced chemical vapour deposition （PECVD） on the interfaces and the microstructures of hydrogenated microcrystalline Si （μc-Si：H） thin films are investigated. The plasma ignition condition is modified by varying the ratio of Sill4 to H2 （RH）. For plasma ignited with a constant gas ratio, the time-resolved optical emission spectroscopy presents a low value of the emission intensity ratio of Ha to Sill＊ （Iuα//SiH＊） at the initial stage, which leads to a thick amorphous incubation layer. For the ignition condition with a profiling RH, the higher IHα/ISiH＊ values are realized. By optimizing the RN modulation, a uniform crystallinity along the growth direction and a denser αc-Si：H film can be obtained. However, an excessively high IRα/ISIH＊ may damage the interface properties, which is indicated by capacitance-voltage （C-V） measurements. Well controlling the ignition condition is critically important for the applications of Si thin films.展开更多
The non-equilibrium between ions and electrons in the hot spot can relax the ignition conditions in inertial confinement fusion[Fan et al.,Phys.Plasmas 23,010703(2016)],and obvious ion-electron non-equilibrium could b...The non-equilibrium between ions and electrons in the hot spot can relax the ignition conditions in inertial confinement fusion[Fan et al.,Phys.Plasmas 23,010703(2016)],and obvious ion-electron non-equilibrium could be observed by our simulations of high-foot implosions when the ion-electron relaxation is enlarged by a factor of 2.On the other hand,in many shots of high-foot implosions on the National Ignition Facility,the observed X-ray enhancement factors due to ablator mixing into the hot spot are less than unity assuming electrons and ions have the same temperature[Meezan et al.,Phys.Plasmas 22,062703(2015)],which is not self-consistent because it can lead to negative ablator mixing into the hot spot.Actually,this non-consistency implies ion-electron non-equilibrium within the hot spot.From our study,we can infer that ion-electron non-equilibrium exists in high-foot implosions and the ion temperature could be~9%larger than the equilibrium temperature in some NIF shots.展开更多
基金Project supported by the National Basic Research Program of China(Grant Nos.G2006CB202601 and 2011CBA00705)the National Natural Science Foundation of China(Grant No.60806020)the Knowledge Innovation Project of Chinese Academy of Sciences(Grant No.KGCX2-YW-383-1)
文摘The influences of the plasma ignition condition in plasma enhanced chemical vapour deposition （PECVD） on the interfaces and the microstructures of hydrogenated microcrystalline Si （μc-Si：H） thin films are investigated. The plasma ignition condition is modified by varying the ratio of Sill4 to H2 （RH）. For plasma ignited with a constant gas ratio, the time-resolved optical emission spectroscopy presents a low value of the emission intensity ratio of Ha to Sill＊ （Iuα//SiH＊） at the initial stage, which leads to a thick amorphous incubation layer. For the ignition condition with a profiling RH, the higher IHα/ISiH＊ values are realized. By optimizing the RN modulation, a uniform crystallinity along the growth direction and a denser αc-Si：H film can be obtained. However, an excessively high IRα/ISIH＊ may damage the interface properties, which is indicated by capacitance-voltage （C-V） measurements. Well controlling the ignition condition is critically important for the applications of Si thin films.
基金This work has been supported by the Foundation of Presi-dent of China Academy of Engineering Physics(Grant Nos.201402037 and 201401040)the CAEP-FESTC(Grant No.R2014-0501-01)the National Basic Research Program of China(Grant No.2013CB34100).
文摘The non-equilibrium between ions and electrons in the hot spot can relax the ignition conditions in inertial confinement fusion[Fan et al.,Phys.Plasmas 23,010703(2016)],and obvious ion-electron non-equilibrium could be observed by our simulations of high-foot implosions when the ion-electron relaxation is enlarged by a factor of 2.On the other hand,in many shots of high-foot implosions on the National Ignition Facility,the observed X-ray enhancement factors due to ablator mixing into the hot spot are less than unity assuming electrons and ions have the same temperature[Meezan et al.,Phys.Plasmas 22,062703(2015)],which is not self-consistent because it can lead to negative ablator mixing into the hot spot.Actually,this non-consistency implies ion-electron non-equilibrium within the hot spot.From our study,we can infer that ion-electron non-equilibrium exists in high-foot implosions and the ion temperature could be~9%larger than the equilibrium temperature in some NIF shots.
