Proposal for ZnS/Mg_xBe_yZn_1-x-yS Quantum Wells

Abstract

An expression is obtained for the resistance force of fractal objects (fractal aggregates, fractal tangles, aerogels) that are moving in a gas. A fractal object is consisdered as a system of independent balls with a radius which is small compared with the free path length of gaseous molecules. The expression for the mobility of fractal aggregates is obtained. It is shown the validity of the Gaidukov statement that a viscosity layer absents on the boundary of a fractal object and gas. Penetrating of a gas inside fractal objects is analyzed.

Effect of Exciton-Longitudinal Optical Phonon Interaction οn Exciton Binding Energies in ZnS/MgxBeyZn1-x-yS Quantum Wells

“…The condition for lattice-matching between ZnS and Mg x Be y Zn 1−x−y S is y = 0.35x [5]. This condition is valid until x = 0.74, where the Zn content (1 − x − y) becomes zero.…”

“…In addition, the exciton binding energies in ZnS/ Mg x Be y Zn 1−x−y S single quantum wells (SQWs) are larger than the room-temperature (RT) thermal energy [5]. If the excitons are stable at RT, exciton transitions can be used for the fabrication of light-emitting devices.…”

“…For this purpose, a large exciton binding energy is required. In our previous study, [5] we calculated the exciton binding energies in ZnS/Mg x Be y Zn 1−x−y S SQWs; for simplification of the calculations, we ignored the effect of exciton-longitudinal optical (LO) phonon interaction on the electron-hole Coulomb interaction. Senger and Bajaj reported that the exciton binding energies calcu- * corresponding author; e-mail: ycd1ngt@yahoo.co.jp lated for QWs increase when the effect of the exciton-LO phonon interaction is considered [6].…”

Effect of Image Charge on Exciton Binding Energy in ZnS/BexZn1-xS Quantum Wells

“…The controllability of heavy-and light-hole transition energies is equivalent to that of those in ZnS/MgBeZnS SQWs. 27) The maximum energy separation between the heavy-and light-hole exciton transitions increases with x and reaches 152.2 meV at x ¼ 0:76.…”