Behavior of photoluminescence energy in polar ZnCdO/ZnO quantum wells under hydrostatic and uniaxial pressures: Linear and nonlinear piezoelectric contributions
Küçük Resim Yok
Tarih
2020
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Academic Press Ltd- Elsevier Science Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Dependence of the photoluminescence (PL) energy (E-PL) in polar ZnCdO/ZnO quantum wells (QWs) on hydrostatic and uniaxial pressures are investigated as regards the Cd concentration of the structures and their physical dimension. The calculations are carried out within the framework of the effective mass and envelope function approximations. The built-in electric field is incorporated into the calculations using a piezoelectric polarization expression up to a nonlinear regime. It is found that the nonlinearity in piezoelectric polarization, under the effect of the hydrostatic pressure, leads to a large built-in electric field up to 5 MV/cm in consequence of the high lattice mismatch existing in the structures. The resulting quantum confined Stark effect causes a decreasing dE(PL)/dp from 23.6 meV/GPa down to even negative values, such as -6.46 meV/GP, for the QWs up to 50 angstrom in width. A linear relationship between E-PL at ambient pressure E-PLO and dE(PL)/dp is obtained in both cases of the hydrostatic and uniaxial pressure applications. It is seen that the relationship is universal in view of the Cd concentration.
Açıklama
Anahtar Kelimeler
ZnCdO, Hydrostatic pressure, Uniaxial pressure, Quantum wells
Kaynak
Superlattices and Microstructures
WoS Q Değeri
Q3
Scopus Q Değeri
Q2
Cilt
139