Title :
Effects of transient ultrasonic switch for amorphous semiconductor superlattices
Author :
Zhang, Xiao-rong ; Gan, Chang-ming ; Mao, G.M. ; Chen, K.J.
Author_Institution :
Inst. of Acoust., Nanjing Univ., China
Abstract :
We found the effects of transient ultrasonic switch due to optical absorption in periodic compositional amorphous semiconductor superlattice a-Si:H/a-SiNx:H films (samples). The effects were observed from the amplitude drop of surface acoustic wave (SAW) while the optic light illuminated the surface of the samples. For the samples, the thickness of the a-Si:H sublayer is varied from 10 Å to 200 Å, and that of the a-SiNx:H sublayer is fixed at 30 Å. Respectively. Two interdigital transducers with center frequency of 136 MHz are used as exciting and receiving transducers for SAW. The results show that, the influence of optical radiation on decreasing SAW amplitude is transient, but on the velocity change of SAW often has some delay. The effects of transient ultrasonic switch depend on the thickness of a-Si:H sublayer and the power of optic light. The optimum thickness is equal to 60 Å
Keywords :
silicon; 10 to 200 angstrom; Si:H-SiN:H; amorphous semiconductor superlattices; interdigital transducers; optical absorption; surface acoustic wave; transient ultrasonic switch; velocity change; Absorption; Amorphous semiconductors; Optical films; Optical superlattices; Optical surface waves; Optical switches; Semiconductor films; Semiconductor superlattices; Surface acoustic waves; Ultrasonic transducers;
Conference_Titel :
Ultrasonics Symposium, 1997. Proceedings., 1997 IEEE
Conference_Location :
Toronto, Ont.
Print_ISBN :
0-7803-4153-8
DOI :
10.1109/ULTSYM.1997.663093
