Double quantum dots as a high sensitive submillimeter-wave detector

A single electron transistor (SET) consisting of parallel double quantum dots fabricated in a GaAs/Al$_{x}$Ga$_{1-x}$As heterostructure crystal is demonstrated to serve as an extremely high sensitive detector of submillimeter waves (SMMW). One of the double dots is ionized by SMMW via Kohn-mode plasma excitation, which affects the SET conductance through the other quantum dot yielding the photoresponse. Noise equivalent power of the detector for wavelengths about 0.6 mm is estimated to reach the order of $10^{-17}$ W/$\sqrt{Hz}$ at 70 mK.Comment: 3 pages, 4 figures, REVTeX, submitted to Appl.Phys.Let

Elastic Mid-Infrared Light Scattering: a Basis for Microscopy of Large-Scale Electrically Active Defects in Semiconducting Materials

A method of the mid-IR-laser microscopy has been proposed for the investigation of the large-scale electrically and recombination active defects in semiconductors and non-destructive inspection of semiconductor materials and structures in the industries of microelectronics and photovoltaics. The basis for this development was laid with a wide cycle of the investigations on the low-angle mid-IR-light scattering in semiconductors. The essence of the technical idea was to apply the dark-field method for spatial filtering of the scattered light in the scanning mid-IR-laser microscope. This approach enabled the visualization of large-scale electrically active defects which are the regions enriched with ionized electrically active centers. The photoexcitation of excess carriers within a small volume located in the probe mid-IR-laser beam enabled the visualization of the large-scale recombination-active defects like those revealed in the optical or electron beam induced current methods. Both these methods of the scanning mid-IR-laser microscopy are now introduced in detail in the present paper as well as a summary of techniques used in the standard method of the lowangle mid-IR-light scattering itself. Besides the techniques for direct observations, methods for analyses of the defect composition associated with the mid-IR-laser microscopy are also discussed in the paper.Comment: 44 pages, 13 figures. A good oldi