Effect of polarization and self-energy on the ground donor state in the presence of conduction band nonparabolicity in GaAs–(Al,Ga)As spherical quantum dot

2007 ◽  
Vol 101 (5) ◽  
pp. 054315 ◽  
Author(s):  
M. K. Bose ◽  
K. Midya ◽  
C. Bose
Keyword(s):  
Quantum Dot ◽  
Conduction Band ◽  
Self Energy ◽  
Spherical Quantum Dot ◽  
Donor State ◽  
Band Nonparabolicity

Effect of electric field, dielectric screening and conduction band nonparabolicity of donor in a quantum dot

2018 ◽  
Vol 32 (10) ◽  
pp. 1850122 ◽  
Author(s):  
A. Rejo Jeice ◽  
Sr. Gerardin Jayam ◽  
K. S. Joseph Wilson
Keyword(s):  
Binding Energy ◽  
Quantum Dot ◽  
Electric Field ◽  
Conduction Band ◽  
Spherical Quantum Dot ◽  
Donor Binding Energy ◽  
Hydrogenic Donor ◽  
Dielectric Screening ◽  
Parabolic Confinement ◽  
Band Nonparabolicity

The effect of electric field, dielectric screening, conduction band nonparabolicity and effective mass mismatch of a hydrogenic donor in a GaAs/Ga[Formula: see text]Al[Formula: see text]As spherical quantum dot is investigated by assuming parabolic confinement using variational method. In the present work we obtain the increase of binding energy by decreasing the dot size for certain dot radii (50 Å) and the screening function gives uniformly larger values for smaller dot size. The effect of electric field and temperature decrease the donor binding energy whereas the conduction band nonparabolicity leads to increased binding energy.

scholarly journals Adjustment of Terahertz Properties Assigned to the First Lowest Transition of (D+, X) Excitonic Complex in a Single Spherical Quantum Dot Using Temperature and Pressure

2021 ◽  
Vol 11 (13) ◽  
pp. 5969
Author(s):  
Noreddine Aghoutane ◽  
Laura M. Pérez ◽  
Anton Tiutiunnyk ◽  
David Laroze ◽  
Sotirios Baskoutas ◽  
...  
Keyword(s):  
Refractive Index ◽  
Quantum Dot ◽  
Energy Region ◽  
Practical Importance ◽  
High Energy ◽  
Spherical Quantum Dot ◽  
Terahertz Region ◽  
Mass Approximation ◽  
Optical Responses ◽  
Temperature And Pressure

This theoretical study is devoted to the effects of pressure and temperature on the optoelectronic properties assigned to the first lowest transition of the (D+,X) excitonic complex (exciton-ionized donor) inside a single AlAs/GaAs/AlAs spherical quantum dot. Calculations are performed within the effective mass approximation theory using the variational method. Optical absorption and refractive index as function of the degree of confinement, pressure, and temperature are investigated. Numerical calculation shows that the pressure favors the electron-hole and electron-ionized donor attractions which leads to an enhancement of the binding energy, while an increasing of the temperature tends to reduce it. Our investigations show also that the resonant peaks of the absorption coefficient and the refractive index are located in the terahertz region and they undergo a shift to higher (lower) therahertz frequencies when the pressure (temperature) increases. The opposite effects caused by temperature and pressure have great practical importance because they offer an alternative approach for the adjustment and the control of the optical frequencies resulting from the transition between the fundamental and the first excited state of exciton bound to an ionized dopant. The comparison of the optical properties of exciton, impurity and (D+,X) facilitates the experimental identification of these transitions which are often close. Our investigation shows that the optical responses of (D+,X) are located between the exciton (high energy region) and donor impurity (low energy region) peaks. The whole of these conclusions may lead to the novel light detector or source of terahertz range.

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