Abstract:

In this study, single crystal Ge layers have been deposited by molecular beam epitaxy on PSi substrate, with different thicknesses (40 nm and 80 nm) at the growth temperature of 400°C. Raman and Atomic force microscopy (AFM) have been applied for investigation of structural and morphological properties in order to explain the photoluminescence properties of the Ge on PSi layers. The results show a stronger Raman intensity of PSi due to change of its optical constant. Similarly, the Si/Ge/PSi sample shows a peak at 399 cm^-1 but with lower intensity compared with that of PSi probably due to the Si emission partially covered by the Ge inside the porous. Besides that, a sharp Raman peak at 298 cm^-1 is observed which reflects Raman active transverse optical mode of the introduced Ge which indicate the growth of Ge with good crystallinity. AFM characterization shows the rough silicon surface which can be regarded as a condensation point for small skeleton clusters to form, with different size of pores. These changes are highly responsible for its photoluminescence in the red wavelength range. This study explores the applicability of prepared Ge/PSi layers for its various applications in advanced optoelectronics field and silicon-on-insulator applications.

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