CdS microcrystals under weak confinement conditions embedded in a polyvinyl alcohol polymer film have been optically characterized by linear absorption and time-resolved luminescence spectroscopy.They are studied in the presence of an external electrical field at low and room temperature and different densities of photoexcited carriers. By applying a voltage of 400 V corresponding to an external electricfield strength of 5 X 10 V/cm, the observed absorption change in this material is Aa/a =0.07. The electrical field produces a redshift of the absorption band which is explained in terms of the quantumconfined Stark effect. In addition, a restoring of the oscillator strength is observed and explained by screening effects of internal fields in the interface region by the photogenerated electron-hole pairs. At high laser excitation an electric-field-induced change of the nonlinear absorption spectrum of ha/a=0. 25 is achieved, giving a considerable modulation of the absorption edge. The electrical field separates the laser excited carriers and the change in the absorption is attributed to a compensation of the many-particle interaction by the external electrical field.
In winter, the reflective properties of ice-and-snow-covered lakes and the surrounding surface covered with snow differ little. Estimation of the albedo becomes especially important in spring when the reflectivity of the ice-covered lakes differs markedly from the surrounding snow-free surface. The measurements of the snow and ice albedo in situ are necessary to ensure adequate analysis of remote sensing data and monitoring of the state of the land ice. A wide range of surface albedo of small boreal ice-covered Lake Vendyurskoe (North-Western Russia) is calculated from observational data of solar radiation obtained in 1995-2000 and 2002-2017. A noticeable variability of albedo due to spring melting and changes in weather conditions is described. Climatic variability (North Atlantic Oscillation (NAO) index, the average monthly air temperature and sum of precipitation in December-March) is analyzed in the context of possible influence on the maximal thickness of snow and white ice, and, consequently, on the spring lake albedo dynamics. In current work to estimate the external heat flux that comes from the atmosphere to the surface of the lake and presumably determines the dynamics of albedo during spring melting, a simple parameter was used: the accumulated sum of positive temperatures, starting from March 1. The obtained prognostic equation of the cubic dependence of albedo on the named parameter demonstrates a different rate of albedo decrease in the melting of snow, white, and congelation ice.
A system of differential equations describing an avalanche multiplication in MIS-structure is derived and numerically solved in frames of the uniform electric field along the interface and infinitely thin inverse layer. The dynamic characteristic of the current, time dependence of the multiplication coefficient, and the current-voltage characteristics are in a good agreement with the experimental results.CocTasneIxa EI mimeHHo pemeHa cHcTeMa nkl@@epeHquanbHMx ypaBHeHtiI1, OnncbIBaml I&l H IIpOUeCC JIaBUHHOrO yMHOHWHHJ3 B Man CTpYKTYpe B IIpkl6JrklmeHklkl OAHOpOnHOrO no llOBepXHOCTU CTPYKTYPbl 3JIeKTYH9eCKOrO IIOnH kl 6eCKOHe9HO TOHKOrO HHBepCklOH-UCTIlKa TOKB, 3aBUCMMOCTb KOe3@@HUkleHTa YMHOECeHEIH OT BpeMeHkl kl BOnbT-aMnepHaH XapaKTepklCTUKa HaXOnRTCH B X O p O l u e M COOTBeTCTBUU C 3KCIIepHMeHTaJIbHMMkl pe3yJlb-TBTBMH. Horo C~O I I . ITonyseHHMe B peaynb~a~e pemeHm ypaBHeHxZt EmraMmecKarr xapawep-~
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.