Orientation of chemical bonds at type-II heterointerfaces probed by polarized optical spectroscopy

Abstract

Time-resolved and cw photoluminescence ͑PL͒ spectra are studied in type-II ZnSe/BeTe multiple quantum wells. Samples with nonequivalent interfaces exhibit a strong in-plane linear polarization of the PL along a ͗110͘ axis. The polarization is stable with respect to an increase in the excitation intensity by many orders of magnitude, to a raising of the temperature up to 300 K and not influenced by applied electric or magnetic fields. The experimental data are discussed in the framework of a tight-binding model taking into account a type-II band alignment and lack of common atom in the ZnSe/BeTe heterosystem.

Breakdown of Rotational Symmetry at Semiconductor Interfaces: a Microscopic Description of Valence Subband Mixing

“…can act on the overall symmetry of the quantum well with the growth procedure. Equivalent trends have recently been reported in the case of BeTe-ZnSe type-II QWs [20,21].…”

Analysis of lattice dynamics and magnetic properties of II‐VI layers and interfaces by Raman spectroscopy

“…For the analysis of the interface, besides photoluminescence [2,3], vibration Raman spectroscopy offers a very high sensitivity. The interfacial bonds give rise to characteristic vibration modes [4].…”

Optical anisotropy of surface-emitting ZnSe/BeTe LEDs

“…In this case the calculation of the interband matrix elements requires the knowledge of the microscopic behavior of the wavefunctions at the interfaces which can be obtained by using the pseudo-potential or tight-binding approach. Application of the tight-binding model allows us to explain the experimental results and to relate the strong polarization degree to the orientation of the chemical bonds at the interface [3,4].…”

“…On the contrary, in type-II structures the radiative recombination is indirect in real space, it arises due to electron-hole overlap within an extremely narrow region adjacent to the interface. Consequently, the transition oscillator strength will be significantly affected by the orientation of the chemical bonds at the interface [4]. We report a very pronounced QCPE in ZnSe/BeTe double-barrier structures (DBS).…”