Exploring the microscopic effects of surrounding matrices (HfO2 and SiO2) on CdSe/ZnS and ZnS/CdSe cylindrical core/shell quantum dot for microelectronic transport applications

Abstract

The primary goal of this study is to comprehensively describe the physical impact of surrounding dielectrix oxides on the electronic and optical properties of a confined electron within CdSe/ZnS and ZnS/CdSe cylindrical core/shell quantum dot (CCSQD). The effective mass approximation and the compact density matrix approach have been employed to compute the energy eigenvalues as well as the optical absorption coefficients (OACs) and the refractive index changes (RICs). Our calculations revealed that the presence of enveloping oxides acts as an additional confinement tool altering the electron energy spectrum. The ZnS/CdSe CCSQD exhibited more pronounced response and the exploitation of the local electric factor can effectively enhance the optical nonlinearity of OACs and RICs. We demonstrated that confined electrons within the ZnS/CdSe CCSQD are subjected to an intense interaction at the microscopic scale with the host medium. In addition, saturation effects in the nonlinear computed coefficients have been meticulously analyzed in terms of size and dielectric surroundings. Our findings demonstrated that electronic band edge states are heavily impacted by the sharp dielectric mismatch occurring at QD/matrix interface which could be exploited for the creation of novel optoelectronic devices in the future.