Effect of dielectric screening on the binding energies and diamagnetic susceptibility of a donor in a quantum well wire

Abstract

The effect of the dielectric screening on donor binding energies in a quantum wire has been estimated. Since the screening function is shown to be significant in a few phenomena like carrier transport, and not so in a few cases like the donor binding energy calculations, five different screening functions have been used in the calculations to see their relative merits. It is observed that the dielectric function obtained by Resta using the Thomas -Fermi approximation not only gives lower estimates of the ionization energies for all well widths (L), but also is shown to vary very rapidly with L. The other functions used are those of Hermanson and Vinsome & Richardson. Using the results of the variational calculations for the finite barrier problem, the diamagnetic susceptibility of a donor as a function of L has also been estimated. Though experimental results are not available, we have compared our results for E ion with other theoretical estimates available in the literature. The agreement is found to be good.

Effect of geometry on the screened acceptor binding energy in a quantum wire

“…Experimental realization of impurity states of acceptor in optical spectra was first addressed by Miller et.al (2) . The effect of spatial variation of dielectric screening on donor in finite and infinite wire was reported by Latha et.al (3) . Similar study is made in infinite (4) and finite (5) Quantum well for both donor and acceptor.…”

Effects of Dielectric Screening Function and Image Charges on Hydrogenic Donor Binding Energy in a Surface Quantum Well

“…20 The effect of spatial dielectric screening on the diamagnetic susceptibility of a donor in low dimensional semiconducting systems like quantum well, quantum well wire and quantum dot in the infinite barrier model has been investigated by Nithiananthi et al 21 The effect of the dielectric screening on donor binding energies in a quantum wire has been estimated by Latha et al . with five different screening functions. 22 Keldysh has shown that in thin films, if the dielectric constant of the film is much larger than that of the substrate, as film thickness decreases, the Coulomb interaction increases strongly. 23 Shik, on the other hand, observed a decrease of conductivity with the film thickness, when screening in thin films is taken into account.…”

“…In contrast, the results reported earlier show that the DSF increases the confinement and hence increases the binding energy for all wellwidths. 18,19,22 The reasons for this difference may be due to the asymmetric nature of the well, and the inclusion of the effect of image charges.…”

The diamagnetic susceptibilities of donors in quantum wells with anisotropic effective mass

“…Moreover, the improvements of spintronics require an extensive study of magnetic properties of low dimensional heterostructures. Also, diamagnetic susceptibility of a hydrogenic donor has been studied for a quantum well [4], and for a quantum dot [5]. In semiconductors with anisotropic carrier effective mass, hydrogenic donors are extended along the heavy mass.…”