Improved Efficiency of ZnO and Ge Purification

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.

Porous Semiconductor Compounds with Engineered Morphology as a Platform for Various Applications

“…With certain technological optimizations, the reported columnar morphology obtained via anodization of bulk substrates could serve as an alternative to other column networks obtained by much more expensive technologies, [55,56] leading to the contamination during their growth which affects the emission properties. [57,58] The approach of electrochemical etching is more prospective while it does not require seed layer, high temperatures, transport gas, etc., taking place not via growth, but through dissolution of bulk material, thus the obtained nanostructures possess the same composition and doping as the bulk crystal.…”