Author :
Doghmane, A. ; Hadjoub, I. ; Doghmane, M. ; Hadjoub, Z.
Abstract :
The discovery of photoluminescence properties of highly porous silicon, PS, has recently attracted considerable research. To enrich the understanding of this material, we carry out an investigation of its elastic properties which are of great importance in any opto-, nano-, micro-device applications. By considering 80%-and 70%-porosity PS layers, we deduced their SAW velocities (longitudinal, VL, and transverse, VT); they were found to be: (VL)80% = 1677 m/s, (VL)70% = 1868 m/s, (VL)80% = 1041 m/s, (VT)70% = 1160 m/s, (VR)80% = 969 m/s and (VR)70% = 1080 m/s. Then, their reflection coefficients and acoustic signatures were calculated, plotted and spectrally analyzed. Hence, the optimal conditions for eventual measurements of these parameters by a scanning acoustic microscope were determined (spherical acoustic lens of 50deg, freon as a coupling liquid and variable operating frequencies: 58 MHz, 142 MHz and 565 MHz).
Keywords :
acoustic emission testing; acoustic microscopy; acoustic wave velocity; elasticity; elemental semiconductors; photoluminescence; porosity; porous semiconductors; reflectivity; silicon; surface acoustic waves; ultrasonic materials testing; SAW; Si; acoustic signatures; elastic parameters; frequency 142 MHz; frequency 565 MHz; frequency 58 MHz; photoluminescence; porosity; reflection coefficients; scanning acoustic microscope; velocity 1041 m/s; velocity 1080 m/s; velocity 1160 m/s; velocity 1677 m/s; velocity 1868 m/s; velocity 969 m/s; Acoustic measurements; Acoustic reflection; Acoustic waves; Frequency; Microscopy; Optical reflection; Optical surface waves; Photoluminescence; Silicon; Surface acoustic waves; acoustic signatures; elastic properties; porosity; porous Si; reflection coefficient; wave velocity;
