Strain effect on the intraband absorption coefficient for spherical CdSe/CdS/ZnSe core-shell-shell quantum dots

In this work, we theoretically calculated the intraband absorption coefficient (IAC) between the 1s and 1p conduction band states for a spherical core/shell/shell quantum dot (CSS-QD) as function of inner and outer shells' sizes with and without the presence of strain effect. The electronic structure for the system is computed in the effective mass approximation framework and the strain effect is considered on the continuum elasticity model. We found out that as we compared the strained and the unstrained system, the former causes that the IAC undergoes a small redshift. A similar behavior occurs as the inner and outer shell size increase. The results show that the strain effect is an important factor that will be considered in these nanostructure type. The incorporation of inner and outer shells allowed us to extend some fractions of eV into the absorption spectrum that could be interesting as a mechanism to control the IAC device design.

Automated summary

In this work, we theoretically calculated the intraband absorption coefficient (IAC) between the 1s and 1p conduction band states for a spherical core/shell/shell quantum dot (CSS-QD). The effects of inner and outer shells' sizes and strain on the IAC were investigated. It was found that both strain and larger shell sizes resulted in a small redshift in the IAC. The findings highlight the importance of considering strain effects and the introduction of inner and outer shells in the design of nanostructures for controlling the IAC.