Innovation in Semiconductor Nanomaterials for Energy Harvesting and Data Storage Applications

Paper ID : 1080-ISCBAS

Authors

Iman A. Mahdy * Al-Azhar University

Abstract

Over many years IV-VI telluride nanocrystals have gained significant attention owing to their excellent properties, which qualified them for infrared detection, thermoelectrics, photovoltaics, and phase change memory applications [1, 2]. Binary and ternary tellurides of Pb and Ge, in particular, have some interesting structural properties. PbTe crystallizes in the cubic rocksalt structure [3, 4], Meanwhile, at room temperature GeTe shows a distorted rock-salt structure along the <111> direction that transforms to cubic at some critical temperature (Tc ~ 700-705 K)[5-7]. Despite the long-time limitation of using the Pb-Ge-Te system in ferroelectric devices application due to its low transition temperature (below room), the current work results (XRD, HRTEM, DR, and P-E dependence) provide evidence for the distorted ferroelectric phase at room temperature. Moreover, the nanocrystalline nature of the prepared samples confirmed by XRD and AFM results, along with the increased Ge content enhanced further the optical and ferroelectric properties. DR measurements showed direct allowed electronic transitions, in agreement with the system's previous literature, within the infrared region with a bandgap decrease from 1.57 to 1.35 eV with increasing Ge content. As a result, The prepared alloys are perfectly compatible with the Near Infra-Red (NIR) sensors’ applications. Finally, the reported hysteresis behavior for Pb-Ge-Te bulk nanocrystals at room temperature confirms the existence of ferroelectric domains within the prepared samples[8].

Keywords

Iv-VI semiconductors, Pb-Ge-Te, Ferroelelctric materials, Near infrared sensors, Noncrystalline, AFM studies

Status: Abstract Accepted