Interface structure effects on optical property of undoped ZnSe/BeTe type-Ⅱ quantum wells

Abstract

The results are reported of the spatially indirect photoluminescence (PL) spectrum measurements performed on undoped ZnSe/BeTe type-Ⅱ quantum wells with special interface structures at low temperatures (5—10 K). The PL spectra have two main peaks that show a weak PL intensity and a low linear polarization degree and that their linear polarizations are contrary to each other, And the PL spectra are strikingly dependent on an applied external electric field perpendicular to the layers. The results show that the special interface structures reduce spatially indirect radiative recombination efficiency and linear polarization degree, and that a weak built-in electric field exists in the heterostructure. With the increase of excitation intensity, the PL peak on high energy side shows a rapid increase. This is explained by the formation of high charge density on both sides of the high energy side interface.