Improved Efficiency of ZnO and Ge Purification

Grygoriy S Pekar,Alexandr F Singaеvsky,Myhailo M Lokshin,Ilya A Vasin,Oleksandr V Dubikovskyi

doi:10.4236/jcpt.2019.93003

Grygoriy S Pekar, Alexandr F Singaеvsky + Show 3 more

Open Access

https://doi.org/10.4236/jcpt.2019.93003

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Abstract

Unconventional ways to improve the efficiency of purification of two different semiconductor materials of current interest, ZnO and Ge, are described. It is shown that, by using chemically assisted vapour transport of ZnO with carbon as a transporting agent, the degree of chemical purity of ZnO can be increased by more than an order of magnitude. It is also found that heating of the molten Ge in the experimentally determined narrow (about 20?C wide) temperature range in which an intense evaporation of certain substances is observed, leads to a significant reduction of germanium contamination. As a result, a subsequent deep purification of pre-heat treated germanium by zone refining can be achieved at twice reduced (as compared with “non-treated” Ge) number of passes of a boat with germanium through the melting zones. Thus, the Ge purification process becomes faster, cheaper and more efficient.

Highlights

As the areas of application of semiconductor materials expand and requirements to their characteristics increase, the problem of improving methods for materials purification remains relevant
It is found that heating of the molten Ge in the experimentally determined narrow temperature range in which an intense evaporation of certain substances is observed, leads to a significant reduction of germanium contamination
For zinc oxide powder purification, we used a method of chemically assisted vapour transport (СVT)

Summary

Introduction

As the areas of application of semiconductor materials expand and requirements to their characteristics increase, the problem of improving methods for materials purification remains relevant. This applies to such widely used materials as ZnO and Ge, despite the fundamental differences in their properties and applications. The potential of zinc oxide for antimicrobial applications in the fields of biomedicine and environmental protection was established [4] For most of these applications, it is desirable to use fairly pure substances. Except for medical purposes, it might be profitable to use high purity ZnO crystals for some technical applications, for example, in electronics, primarily as substrates for GaN light-emitting diodes and lasers instead of hydrothermally grown ZnO crystals contaminated with impurities during growth. This article describes unconventional, fairly simple and affordable ways for increasing efficiency of ZnO purification as well as of Ge zone-refining

Zinc Oxide Purification

Germanium Purification

Conclusions