Accession Number : ADP007862

Title :   LO Phonons in CdS(x)Se(1-x) Semiconductor Microcrystallites,

Corporate Author : TOKYO UNIV (JAPAN)

Personal Author(s) : Kobayashi, Takayoshi ; Nomura, Shintaro

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : It is of interest and importance to study semiconductor microcrystallites as three dimensionally confined system in conjecture with one dimensionally confined quantum well systems. Because the oscillator strengths are concentrated on several discrete states, microcrystallites are expected to have large optical nonlinearities. To accomplish this large optical nonlinearities, however, the spectral width play a major role. The intrinsic width is introduced by exciton-phonon coupling rather than an inhomogeneous width which originates from the distribution in the size of microcrystallites. Recently, couplings to longitudinal optical (LO) phonons were investigated by various groups and it was suggested that a microcrystallite of smaller radius exhibits larger coupling to LO phonons because of the increase in couplings to shorter wavelength phonons by the confinement of the exciton wave functions in real space. In the former part of this paper, the temperature dependence of the exciton energy and the width is investigated by the modulation spectroscopy of the absorption. In the latter part, the exciton-LO phonon coupling constant (Huang-Rhys parameter) is investigated theoretically.

Descriptors :   *OSCILLATORS, *ELECTROOPTICS, ABSORPTION, CONSTANTS, COUPLINGS, DISTRIBUTION, ENERGY, EXCITONS, FUNCTIONS, MODULATION, PAPER, PARAMETERS, PHONONS, SEMICONDUCTORS, SPECTROSCOPY, TEMPERATURE, WAVE FUNCTIONS, WIDTH, JAPAN.

Subject Categories : Electrooptical and Optoelectronic Devices

Distribution Statement : APPROVED FOR PUBLIC RELEASE