M. Suffczyński

Binding energy of the biexcitons

Abstract The binding energy of the biexciton is shown to vary monotonically with the electron-to-hole effective mass ratio.

Binding energy of the biexcitons in isotropic semiconductors

Abstract The dependence of the binding energy W of the biexciton on the electronhole mass ratio σ is discussed. The bounds from above and from below on the possible curves y = W (σ) have been obtained. In particular, the upper bound implies a positive binding of the biexcitons in the whole interval of the parameter σ. The bounds on W (σ) have been compared with experimental results on biexcitons in semiconductors.

Effective Hamiltonian for few-particle systems in polar semiconductors

Abstract The interaction between carriers in semiconductors is considered, including the coupling with LO-phonon field. The effective Hamiltonian, derived by the variational method, is valid for any values of the electron-phonon coupling constant. Applying it to the problem of exciton in Cu2O, CuBr and CuCl, we obtain the energies which agree well with the experimental spectra. Owing to its simple form this Hamiltonian may be useful for few-particle systems.

Dependence of the exchange splitting in excitons on the interatomic distance

Abstract The exchange splitting observed in excitons depends exponentially on the interatomic distance of the cation and anion of the compound.

Shallow acceptor wavefunctions with correct asymptotic behaviour

Abstract The wavefunction of the shallow acceptor in Ge is studied in the spherical approximation of Baldereschi and Lipari. The solution of the acceptor problem in the asymptotic limit is used for construction of trial functions. The functions composed of a few exponentials yield the ground state energy of −9.9 meV and possess the asymptotic behaviour accounting well for the hopping conductivity dependence on the acceptor concentration.

The influence of the lattice polarization on the biexciton binding energy

Abstract The ground state of the biexciton in the lattice polarization field using both Haken and recently derived effective Hamiltonians is studied. The variational wave function possessing the full symmetry of the complex and allowing the analytical evaluation of the energy matrix elements is proposed. The biexciton binding energy is calculated as a function of electron-phonon coupling constant and of phonon energy in the case of equal electron and hole masses.

Conduction band edge of tellurium

Conduction band edge of Tellurium is described in K.p approximation and magnetic levels (H‖C) are given.

Variational wave functions for the biexciton in polar semiconductors

Abstract Biexciton ground state energy has been calculated using several trial functions which possess proper symmetry, allow analytical evaluation of the energy matrix elements and include electron-electron and hole-hole correlations. Lattice polarization has been taken into account by means of the effective Hamiltonian with the potential being the sum of Coulomb, Yukawa and exponential terms. The average distances between the particles and the oscillator strengths of the exciton-biexciton conversion have been computed for the optimum trial function.

Phonon replicas of bound exciton recombination

Abstract The relative intensities of the LO phonon replicas of the bound exciton recombination line are calculated in the effective mass approximation. The intensity ratio of the successive replicas and the oscillator strength are proportional to functionals of the bound exciton envelope. The functionals are monotonic functions of the electron to hole effective-mass ratio.

Acceptor ground state in tellurium under hydrostatic pressure

Abstract Acceptor ground state energy in tellurium under hydrostatic pressure is estimated by a variational calculation.