Carrier Localization and Polarized Photoluminescence of GaInP2 Alloy with Spontaneous Atomic Ordering

Abstract

GaInP2 is a technologically important energy material for high-power red-color LDs [1] and high-efficiency solar cells [2, 3]. Therefore, its optical properties and electronic strictures are of particularly interest. In particular, so-called local spontaneous CuPt-type atomic ordering exists in this important energy material, which has been shown to have strong impact on the electronic structures and optical properties of GaInP2 alloy. In this talk, we report an in depth investigation into the carrier localization and polarized photoluminescence (PL) spectra of GaInP2 alloy. By examining variable-temperature polarized PL spectra in detail, it is found that the luminescence from GaInP2 is composed of two components: polarized and non-polarized parts. These two components exhibit dissimilar temperature dependence. The former is ascribed to the emission of carriers localized in the ordered domains while the latter to the emission of carriers localized in the disordered regions. Thermal activation and transfer of localized carriers from the ordered domains to the disordered regions was revealed and characterized with a small thermal activation energy of 10 meV [4].