Photoacoustic Imaging of Compositional Variations in Hg/sub 1-X/Cd/sub X/Te Semiconductors

摘要

Scanned image microscopy utilizing photoacoustic (PA) detection under certain experimental conditions can image spatial variations in various material properties that have a role in PA signal generation. The properties involved are related to the four primary processes that occur in the PA signal generation sequence. These include (1) reflection and (2) absorption of incident light by the sample followed by (3) deexcitation and (4) transport of the absorbed energy. In the measurements performed, a fraction of the absorbed energy that evolves as heat is transferred into a gas adjacent to the sample. The acoustic signal is generated in the gas by thermal expansion and sensed by a transducer. The preliminary work reported demonstrates the possibility of imaging compositional variations in the alloy semiconductor Hg/sub 1-x/Cd/sub x/Te. (ERA citation 06:011299)