Panya Kheanumkeaw, Supasarote Muensit and Patara Aiyarak

pp. 623 - 628

Abstract

The inverse piezoelectric effect, in which the strains were electrically induced, in a single crystal of
GaAs and in a multilayer structure of Al_xGa_1-xAs/GaAs was measured using a simple optical system, i.e.,
Michelson interferometer. An ac driving voltage was applied to the sample to produce a change in the order
of 10^-13 m in sample thickness. These changes were detected by the optical system to give the sample displacement as a function of applied driving voltage. The slope of the plot of this relationship led to the piezoelectric
coefficients of (2.8±0.1)×10^-12 and (3.9±0.1)×10^-12 m/V for GaAs and Al_xGa_1-xAs/GaAs, respectively. The first
agreed well with reported values and the latter was the first report for Al_xGa_1-xAs/GaAs. Owing to the
equality for the inverse effect and the direct effect, in which an electric field can be mechanically induced,
it is anticipated that in the absence of external electric field, the internal piezoelectric field can be induced
in the multi-layered semiconductor.

Keywords

• piezoelectric
• interferometer
• semiconductor