Effects of electric field intensity and dielectric mismatch on hydrogenic impurity photoionization cross section in PbSe/CdSe core/shell quantum dot
Physics Letters, Section A: General, Atomic and Solid State Physics, cilt.556, 2025 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Teknik Not
- Cilt numarası: 556
- Basım Tarihi: 2025
- Doi Numarası: 10.1016/j.physleta.2025.130840
- Dergi Adı: Physics Letters, Section A: General, Atomic and Solid State Physics
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Compendex, INSPEC, MathSciNet, Philosopher's Index, zbMATH
- Anahtar Kelimeler: Binding energy, Hydrogenic impurity, Photoionization cross-section, Stark shift, Surrounding medium
- Sivas Cumhuriyet Üniversitesi Adresli: Evet
Özet
This study seeks to scrutinize the effects of dielectric constant mismatch of the surrounding medium on impurity binding energy (BE) and photoionization cross-section (PICS) of PbSe/CdSe core/shell spherical quantum dots (CSSQDs), both with and without an external electric field (EF). Employing the variational method (VM) within the effective mass approximation (EMA), we consider a hydrogenic impurity located at the center of isolated CSSQDs and those embedded in dielectric matrices such as silicon dioxide (SiO₂) and polyvinyl alcohol (PVA). The analysis focuses on the effects of the core-to-shell radii ratio, dielectric mismatch, and EF intensity. The study explores impact of the core/shell radii ratio, dielectric mismatch, and EF intensity. Our results reveal that BE and PICS are affected significantly by dielectric mismatch, with image charge effects modifying the confinement potential. BE exhibits a nonlinear dependence on core and shell dimensions due to the interplay between quantum confinement and dielectric mismatch. An applied EF reduces BE and shifts the PICS peak due to carrier separation. Moreover, embedding the CSSQDs in different dielectric environments further modulates the optical response, underscoring the critical role of the surrounding matrix. These findings provide valuable guidance for designing optoelectronic and photonic devices such as photodetectors and sensors based on PbSe/CdSe CSSQDs.