Theory of Polar Corrections to Donor Binding

We calculate the optical phonon correction to the binding energy of electrons to donors in cubic materials. Previous theories calculated the Rydberg energy reduced by the effective mass and the static dielectric function. They omitted an important energy term from the long-range polarization of the ionized donor, which vanishes for the neutral donor. They also omitted the donor-phonon interaction. Including these terms yields a new formula for the donor binding energy

Estados excitados de impurezas y propiedades colectivas en heteroestructuras semiconductoras

IP 1106-05-022-92PONENCIA(S) EN CONGRESO: Helicones y modos localizados ensuper-redes ideales / J. C. Granada. -- En:;Memorias Escuela Nacional de Fisica Teorica (8 : 1992 : Cali,Colombia). -- Cali, 1992. -- p. -- 28 cm. --;Impurezas hidrogenoides poco profundas en puntos cuantiaosesfericos de GaAs-(Ga, Al) As / S. T. Perez;Merchancano, N. Porras Montenegro. -- En: Memorias EscuelaNacional de Fisica Teorica (8 : 1992 : Cali,;Semiconductors (22 : 1995 : Vancouver, Canada). -- Vancouver,1995. -- p.-- 28 cm. -- Acceptor energy levels;in GaAs/AlGaAs quantum wells in the presence o fan external magnetic field/ Q. X. Zhao. ... [et. al]. --;Colombia). -- Cali, 1992. -- p. -- 28 cm. -- Binding energiesand densityof impurity states of shallow;hydrogenic impurittes in spherical GaAs-(Ga,Al) quantum dots /N. Porras Montenegro, S. T. Perez Merchancano,;A. Latge. -- En: Memorias Escuela Nacional de Fisica Teorica (8: 1992 : Cali, Colombia). -- Cali, 1992. -- p.; 28 cm. -- Semiconductores III-V en sistemas de baja dimensionalidad: efectos del confinamiento cuantico /;Nelson Porras. -- En: Congreso Nacional de fisica (15 : 1993 sep: 6-10 :Armenia, Quindio). -- Armenia, 1992.; p. -- 28 cm. -- Apantallamiento espacialmente dependiente enel calculode la energia de enlace de;impurezas hidrogenoides en hilos cuantiaos de GaAs con confinamiento infinito / A. Perca, N. Porras. -- En:;Congreso Nacional de fisica (15 : 1993 sep : 6-10 : Armenia, Quindio). --Armenia, 1992. -- p. -- 28 cm. --;Energia de enlace de impurezas hidrogenoides en puntos cuanticosde GaAs-(Ga,Al)As con apantallamiento;espacialmente dependiente / H. Paredes, J. C. Cuervo, N. Porras.'-- en: Congreso Nacional de fisica (15 : 1993;sep : 6-10 : Armenia, Quindio). -- Armenia, 1992. -- p. --28cm. -- Modelos de ising diluidos por sitio y por;enlace y su aplicacion al sistema Fe-Al / A. Osorio. ... [et.al]. -- En:Congreso Nacional de fisica (15 :;1993 sep : 6-10 : Armenia, Quindio). -- Armenia, 1992. --p. --28 cm. --Funciones de green en super redes;semiconductoras con una capa electronica bidimensional defectuosa / G. Becerra, J. C. Granada. -- En: Congreso;Nacional de fisica (15 : 1993 sep : 6-10 : Armenia, Quindio).--Armenia,1992. -- p. -- 28 cm. -- Electric;and magnetic field effects on donor transition energies inGaAs-(Ga,Al)AsAs quantum wells / N. Porras;Montenegro, A. Latge, Luz E. Olivera. -- En: InternationalConference on the Physics on the Physics of;p. 145-148. -- Estado 1S2 para una impureza D en un puntocuantico / L. D.Mikhailov, F. J. Betancur, F.;Duran. -- En: Revista Colombiana de Fisica. -- Vol. 28 (1996);p. 150. --The role of applied magnetic fields;on the binding energy of excited states of hydrogenic impuritiesin cylindrical GaAs-(Ga,Al)As quantum;impurities in cylindrical GaAs)As quantum well wires / P.Villamil. -- En:Revista Colombiana de Fisica. --;Vol. 28 (1996); p. 127-130. -- Influence o fan applied electricfield on the energy of the ground state in;GaAs-(Ga,Al)As quantum boxes / Julio Cesar Lozano C., Nelson Porras Montenegro. -- En: Revista Colombiana de;Fisica. -- Vol. 28 (1996); p. 119-122. -- The role of appliedelectric fields on the binding energies of;shallow donor impurities in GaAs quantum well wires / A. Montes,C. A. Duque, N. Porras Montenegro. -- En:;Revista Colombiana de Fisica. -- Vol. 28 (1996); p. 123-126. -The effectsof quantum confinement on the;binding energy of hydrogenic impuriries in low dimensionalsystems / J. J.Vivas Moreno, N. Porras Montenegro.;C. Cuero Yepez, N. Porras montenegro. -- En: Journal of AppliedPhysics. -- Vol. 75, no 10 (May. 1994); p.;5150-5153. -- Donor 1s-2p transitions in doped GaAs-Ga1-xAlxAsquantum wells: effects of electric and magnetic;fields / A. Latge, N. Porras Montenegro, Luiz E. Oliveira.--En: PhysicalReview B. -- Vol. 51, no. 4 (Jun.;1995); p. 2259-2263. -- 1s-2p infrared-absorption spectraof donor-doped quantum wells Ander electric and;magnetic fields / A. Latge, N. Porras Montenegro, Luiz E.Oliveira. -- En:Physical Review B. -- Vol. 51, no.;19 (May. 1995); p. 13344-13348. -- Local magnetoplasmon modesof a semiconductor superlattice with broken;translational symmetry / J. C. Granada. -- En: Brazilian Journalof Physics. -- Vol. 26, no. 1 (Mar. 1996); p.;2-4. -- Optical absorption spectra associated with shallowdonorimpurities in spherical infinite well GaAs;quantum dots / J. Silva Valencia, N. Porras Montenegro. --En:Journal ofApplied Physics. -- Vol. 81, no. 2;(Jan. 1997); p. 901-904. -- The binding energies of shallow donor impurities in GaAs quantum well wires under.;Amsterdam, 1996. -- p. 28 cm. -- Magnetic field effects ontheoptical absorption spectra associated with;shallow impurities in quantum wells / L. H. M. Barbosa. ... [et.al]. -- En: Shallow-Level Centers in;Semiconductors (7 : 1996 Jul : 17-19 : Amsterdam, Holanda). --Amsterdam,1996. -- p. 28 cm. -- Photon green;tensor of a layered two dimencional electron gas in an externalmagnetic field / John H. Reina E., Juan C.;Granada E. -- En: Conference Proceedings (1994 Sep : 19-20,125Cancun, Mexico). -- Cancun, 1994. -- p. -- 28;cm. -- Collective Excitations and Coupling Between CuO2 Layersin Superconducting Systems with Two Layers per;Cell / J. M. Calero, J. C. Granada. -- En: Surfaces, Vacuum andtheir applications (1994 : Cancun, Mexico). --;Cancun, 1994. -- p. -- 28 cm. -- ARTICULO(S) EN REVISTA: El efecto del confinamiento cuantico en la energia de;enlace de impurezas hidrogenoides en sistemas de baja dimensionalidad / J.Vivas, A. Perea, N. Porras. -- En:; En: Revista Colombiana de Fisica. -- Vol. 28 (1996); p.115-118. -- Optical absorption spectra associated;to shallow hydrogenic impurities in spherical GaAs-(Ga,Al)As quantum dots/ H. Paredes Gutierrez, J. Silva;Valencia, N. Porras Montenegro. -- En: Revista Colombianade Fisica. -- Vol. 29 (1997); p. 87-90. -- Estados;superficiales en superredes / Alvaro Rugeles Perez, Juan Bautista Florez.'-- en: Revista colombiana de fisica.; Vol. 29 (1997); p. 91-94. -- Hydrogenic impurities in GaAs-(Ga,Al)As quantum dots / N. Porras Montenegro,;S. T. Perez Merchancano. -- En: Physical review B. -- Vol.46no. 15 (Oct. 1992); p. 9780-9783. --;Aceptor-related photoluminescence study of GaAs-(Ga,Al)Asquantum-well wires / Luiz E. Oliveira, Andrea Latge,;Nelson Porras Montenegro. -- En: The International SocietyforOptical Engineering. -- Vol. 1675, no 4 (1992);p. 151-159. -- Aceptor-related photoluminescence spectra of GaAsquantum wire microcrystals: a model;calculation / Luiz E. Oliveira, N. Porras Montenegro, Andrea Latge. -- En:Physical review B. -- Vol. 47, no.;20 (May. 1993); p. 13864-13867. -- Spatially dependent screeningcalculation of binding energies of hydrogenic;impurity states in GaAs-(Ga,Al)As quantum-well wires / N.PorrasMontenegro. -- En: Journal of Physics:;Condensed Matter. -- Vol. 5 (1993); p. 367-368. -- Bindingenergies and density of impurity states in;spherical GaAs-(Ga,Al)As quantum dots / N. Porras Montenegro,S.T. PerezMerchancano. -- En: Journal of;Applied Physics. -- Vol. 74, no 12 (Dec. 1993); p. 7624-7626.--Effect ofspatially dependent screening on;the binding energy of shallow impurities in spherical GaAs-(Ga,Al)As quantum dots / H. Paredes Gutierrez, J.;Revista Colombiana de Fisica. -- Vol. 27 (1995); p. 567-569. --Mapeo dimensional para impurezas hidrogenoides;confinadas en pozos cuantiaos / I. mikhailov, F. Betancur,C.Garcia. -- En: Revista Colombiana de Fisica. --;Vol. 27 (1995); p. 571. -- Efecto del campo electrico sobre unhilo cuantico de GaAs con una impureza presente;y confinamiento de GaAs con una impureza presente y confinamiento infinito/ A. Montes, N. Porras. -- En:;Revista Colombiana de Fisica. -- Vol. 27 (1995); p. 607-609. --The role of magnetic fields on donor is;excited states transitions in on center doped GaAs-(GA,AL)AS quantum wells/ A. Latge, N. Porras, L. Olivera.; En: Revista Colombiana de Fisica. -- Vol. 27 (1995); p.591-594. -- Calculo de correlaciones entre Tc y las;propiedades electronicas y fononicas en los nuevos superconductores / J. Giraldo, R. Baquero. -- En: Revista;Colombiana de Fisica. -- Vol. 27 (1995); p. 595. -- Estados deimpurezas donadoras en sistemas de baja;dimensionalidad de GaAs bajo el efecto de un campo electrico externo / C.A. Duque. -- En: Revista Colombiana;de Fisica. -- Vol. 28 (1996); p. 131-136. -- Electromagnetic propagator ofa semiconductor superlattice with;broken translational symmetry in an external magnetic field /J.H. Reina,J. C. Granada E. -- En: Revista;Colombiana de Fisica. -- Vol. 28 (1996); p. 137-140. -- Effectof the excitonic binding energy in GaAs-GaAsAl;spherical quantum dots / L. sanz D., J. C. Granada E. -- En: Revista Colombiana de Fisica. -- Vol. 28 (1996);International Conference on the Physics of Semiconductors(22:1995 : Singapore). -- Singapore, 1995. -- p.; 28 cm. -- Magnetoluminescence spectra associated to acceptorsin GaAs-(Ga,Al)As superlattices / A. Latge.;... [et. al]. -- En: Shallow-Level Centers in Semiconductors (7: 1996 Jul: 17-19 : Amsterdam, Holanda). --; Vol. 81, no. 2 (Jun. 1997); p. 7887-7891. -- Photoluminescence study ofshallow acceptors in GaAs spherical;quantum dots / J. Silva Valencia, H. Paredes Gutierrez, N.Porras Montenegro. -- En: Journal of Luminescence.; Vol. 72, no. 74 (1997); p. 403-405. -- Photoluminescence spectra associated to shallow acceptors in;GaAs-Ga1-xAlxAs quantum dots / H. Paredes Gutierrez, J. SilvaValencia, N.Porras montenegro. -- En: Brazilian;Journal of Physics. -- Vol. 27, no. 4 (Dec. 1997); p. 248-251.-'- Opticalcharacterization of Pb1-xSnxTe;layers by infraerd transmission / S. O. Ferreira. ... [et.al].'-- en: Brazilian Journal of Physics. -- Vol.;27, no. 4 (Dec. 1997); p. 252. -- Theoretical calculationof theminibandto acceptor magnetoluminescence of s;6234-6237

Donor impurity in vertically-coupled quantum-dots under hydrostatic pressure and applied electric field

In this work we make a predictive study on the binding energy of the ground state for hydrogenic donor impurity in vertically-coupled quantum-dot structure, considering the combined effects of hydrostatic pressure and in growth-direction applied electric field. The approach uses a variational method within the effective mass approximation. The low dimensional structure consists of three cylindrical shaped GaAs quantum-dots, grown in the z-direction and separated by Ga1-xAlxAs barriers. In order to include the pressure dependent Γ – X crossover in the barrier material a phenomenological model is followed. The main findings can be summarized as follows: 1) for symmetrical and asymmetrical dimensions of the structures, the binding energy as a function of the impurity position along the growth direction of the heterostructure has a similar behavior to that shown by the non-correlated electron wave function with maxima for the impurity in the well regions and minima for the impurity in the barrier regions, 2) for increasing radius of the system, the binding energy decreases and for R large enough reaches the limit of the binding energy in a coupled quantum well heterostructure, 3) the binding energy increases for higher Aluminum concentration in the barrier regions, 4) depending of the impurity position and of the structural dimensions of the system (well width and barrier thickness) – and because changing the height of the potential barrier makes possible to induce changes in the degree of symmetry of the carrier-wave function –, the electric field and hydrostatic pressure can cause the impurity binding energy increases or decreases, and finally 5) the line-shape of the binding energy curves are mainly given by the line-shape of the Coulomb interaction.

Donor-impurity related binding energy and photoinization cross-section in quantum dots: electric and magnetic fields and hydrostatic pressure effects

We have studied the behavior of the binding energy and photoionization cross-section of a donor-impurity in cylindrical-shape GaAs-Ga0.7Al0.3As quantum dots, under the effects of hydrostatic pressure and in-growth direction applied electric and magnetic fields. We have used the variational method under the effective mass and parabolic band approximations. Parallel and perpendicular polarizations of the incident radiation and several values of the quantum dot geometry have also been considered. Our results show that the photoionization cross-section growths as the hydrostatic pressure is increased. For parallel polarization of the incident radiation, the photoionization cross-section decreases when the impurity is shifted from the center of the dot. In the case of perpendicular polarization of the incident radiation, the photoionization cross-section increases when the impurity is shifted in the radial direction of the dot. For on-axis impurities the transitions between the ground state of the impurity and the ground state of the quantum dot are forbidden. In the low pressure regime (less than 13.5 kbar) the impurity binding energy growths linearly with pressure, and in the high pressure regime (higher than 13.5 kbar) the binding energy growths up to a maximum and then decreases. Additionally, we have found that the applied electric and magnetic fields may favor the increase or decrease in binding energy, depending on the impurity position