Obtaining of the substrates of II-VI compounds and solid solutions for nanoporous structures

Abstract

The wide band-gap II-VI semiconductors and solid solutions on their basis have large perspectives to be used in optoelectronics, solar energy and spintronics. Substrates of these materials could be widely utilized for fabrication of nanoporous matrices (templates) used for obtaining nanowires and nanotubes with various diameters and lengths. These nanostructures can be used as elements of LEDs, plate lenses, components of integrated optical circuits etc. One of the most interesting applications is solar energy converters with improved performance and cost effectiveness due to increased optical absorption in the region of nanostructured p-n junction and smaller necessary thickness of corresponding layers. The easiest and cost effective method to obtain nanoporous structures is anodic etching. However, the technology development for II-VI compounds is still on the beginning stage. This paper deals with the problems of growing homogeneous substrates of the widest band gap II-VI semiconductors (ZnSe, ZnS, ZnO) and solid solutions on their basis (ZnCdS, ZnSSe) with controlled electrical parameters. Prospects of these materials utilization for preparing nanoporous matrices by means of electrochemical etching are also estimated. Various methods of growth and doping of II-VI compounds are analyzed by examination of their morphology, electrical, luminescence and optical properties. The results of nanostructuring using various electrolytes are shown. The prospects of ZnSe and ZnCdS utilization for obtaining nanoporous arrays with porous diameters up to 30 nm are demonstrated. Also, the complexity of obtaining the nanoporous matrices on ZnS, ZnSSe and ZnO substrates is analyzed.