Research / 2019 / Article / Fig 1

Research Article

In Situ Observation of Crystalline Silicon Growth from SiO2 at Atomic Scale

Figure 1

Dose and temperature dependence of Si nanocrystal formation under 300 keV electron irradiation. (a1–a8) False-color TEM images and atomic models show the dynamics of Si nanocrystal formation at 400°C. (a1) Amorphous SiO2. (a2) Formation of amorphous SiO NPs in SiO2. (a3–a8) The crystalline Si nanoparticle nucleates from an amorphous SiO nanoparticle and expends with an increase of the irradiation dose. (b1–b3) Formation process of SiO NPs at 25°C with an increase of the dosage. The initial rough surface becomes smooth at first, then amorphous SiO NPs appear at this surface, highlighted by the cyan dashed line. (b4) Crystalline Si nucleus in a SiO nanoparticle. (c1, c2) Growth process of c-Si NPs at 600°C under different dose rates. (d) EELS of Si edge at 25°C under different doses, confirming the formation of elemental Si. The doses are shown by yellow numbers with the unit of 106 C m-2.