Urbachs rule peculiarities in structures with CdSxSe1-x nanocrystals

2019-12-13 13:51:02

rule absorption induced phonon exciton

责任者: Kunets, V.P.;Kulish, N.R.;Kunets, V.P.;Lisitsa, M.P. 单位: Inst. of Semicond. Phys., Acad. of Sci., Kiev, Ukraine 来源出处: Semiconductor Physics Quantum Electronics Optoelectronics(Semicond. Phys. Quantum Electron. Optoelectron. (Ukraine)),2002//,5(1):9-15 摘要: We have found that the long wavelength fundamental absorption edge of CdSxSe1-x nanocrystals grown in an oxide glass follows to the generalized Urbach rule that takes into account both the dynamic (phonon induced) and static (defect induced) disorders of nanocrystal lattice. Temperature intervals with the dominant influence of both disorders on the absorption edge were determined. We have also estimated Urbach rule constants comparing them with the bulk ones. Using various Urbachs rule theories we analyzed the most considerable changes of nanocrystal parameters when their sizes are decreased down to the quantum scale. It was found that the exciton-phonon coupling constant and exciton localization one are increased; the average electric fields induced by phonons and charged point defects are also increased 关键词: absorption coefficients;cadmium compounds;electric field effects;II-VI semiconductors;nanostructured materials;phonon-exciton interactions;point defects;ultraviolet spectra;visible spectra;Urbachs rule peculiarities;CdSxSe1-x nanocrystals;long wavelength absorption edge;dynamic phonon induced disorders;static defect induced disorders;exciton-phonon coupling constant;exciton localization;electric fields;phonons;charged point defects;CdSxSe1-x