Photostimulated impurity absorption of ultrasound in semiconductor nanostructures

Abstract

Acoustic waves switch based on meta-fluid phononic crystals J. Appl. Phys. 112, 044509 (2012) Probing near-normally propagating bulk acoustic waves using pseudo-reflection geometry Brillouin spectroscopy AIP Advances 2, 032157 (2012) Multiple-band transmission of acoustic wave through metallic gratings Appl. Phys. Lett. 101, 061912 (2012) Analysis of spherical thermo-acoustic radiation in gas AIP Advances 2, 032106 (2012) Acoustic properties of Kel F-800 copolymer up to 85 GPaThe problem of attenuation of ultrasound in a semiconductor with a quantum well structure with infinite potential barriers is tackled for the case in which the acoustic lattice vibrations interact with impurity centers in the presence of an exciting laser field. The electron transitions from an acceptor-impurity ''band'' to the first quantized energy level of the conduction band, forbidden in the absence of the laser field for the absorption of an acoustic wave quantum, become permitted in the presence of the external high frequency field. The external laser field will then supply the energy deficit for the electron to make the transition to absorb the acoustic phonon. The total ultrasound absorption coefficient ␣ T was calculated using second-order perturbation theory and the result was specialized for the case of a GaAs/AlGaAs quantum well sample. It was found that ␣ T is a fairly large quantity as compared with its value in bulk as the well width decreases from values corresponding to the almost bulk situation.

Effect of an intense laser field on donor impurities in spherical quantum dots

“…Nunes et al [22] have tackled the problem of attenuation of ultrasound in a semiconductor with a quantum well structure with infinite potential barriers for the case in which the acoustic lattice vibrations interact with impurity centers in the presence of an exciting laser field.…”

Effects of ultrasound on the microenvironment in reverse micelles and synthesis of nanorods and nanofibers

“…42 Some of the most important aspects of sonochemistry recently, are its applications in material chemistry. Diverse applications of ultrasound have been exploited in inorganic nanostructured materials synthesis, [43][44][45] biomaterials preparation (protein microspheres) 46,47 and sonochemical synthesis of polymers. [48][49][50] Some nanorods or nanowires of inorganic materials have been synthesized using sonochemical methods.…”

Ultrasonication-Induced Formation of Silver Nanofibers in Reverse Micelles and Small-Angle X-ray Scattering Studies

“…It is well known that ultrasonic radiation in liquids has a variety of physical and chemical effects that are derived from acoustic cavitation, which can provide a unique method for driving chemical reactions under extreme conditions. 26 Diverse and promising applications of ultrasound such as the synthesis of nanostructured materials in various forms, [27][28][29] the preparation of biomaterials, 30,31 and modifications to polymers and polymer surfaces have been exploited in materials chemistry. 4 Recently, many groups have reported the synthesis of nanorods or nanowires of inorganic materials using sonochemical methods.…”

“…It is well known that ultrasonic radiation in liquids has a variety of physical and chemical effects that are derived from acoustic cavitation, which can provide a unique method for driving chemical reactions under extreme conditions − the preparation of biomaterials, , and modifications to polymers and polymer surfaces − have been exploited in materials chemistry . Recently, many groups have reported the synthesis of nanorods or nanowires of inorganic materials using sonochemical methods. − For example, Nikitenko et al − have successfully synthesized tungsten sulfide and tungsten oxide nanorods via ultrasonic irradiation of a solution of tungsten hexacarbonyl W(CO) 6 in diphenylmethane (DPhM) at 90 °C followed by heating and annealing processes at temperatures higher than 800 °C.…”