Epitaxial Piezoelectric Pb() Thin Films on Silicon for Energy Harvesting Devices
Figure 1
Evolution of RHEED pattern during the growth of a STO layer. The patterns shown are taken with the electron beam along the direction. (a) As-received Si wafer (001), the diffuse background indicates the presence of a native amorphous layer of SiO2; (b) crystalline Si surface after a thermal treatment in vacuum: the appearance of fractional spots (0,1/2) due to Si dimers indicates the complete removal of SiO2, (c) 2× surface reconstruction corresponding to the deposition of half monolayer (ML) of Sr in vacuum at high temperature, (d) 3× reconstruction corresponding to the deposition of half ML of Sr in vacuum at low temperature, (e) 1 ML of SrO, (f) 3 ML of crystalline STO.
