Nanostructures and methods for manufacturing the same

A method for forming an epitaxial layer of a second crystalline material on a substrate of a first crystalline material, said first crystalline material being different from said second crystalline material, the method comprising:

• forming on said substrate an array of catalytic seed particle material areas;
• forming a layer of mask material around the seed particle areas;
• catalytically growing underneath the catalytic seed particle areas initial growth areas of a crystalline phase of said second crystalline material;
• and
• continuing to grow said second crystalline material, using said initial growth areas as growth sites, thereby to create an epitaxial layer of said second crystalline material extending over said substrate of said first crystalline material.

A method for forming an epitaxial layer of a second crystalline material on a substrate of a first crystalline material said first crystalline material being different from said second crystalline material, the method comprising:

• forming V-shaped grooves in an upper surface of said substrate of the first crystalline material;
• providing a plurality of catalytic seed particles in said V-shaped grooves;
• growing nanowhiskers of said second crystalline material from the catalytic seed particles;
• and
• continuing to grow said second crystalline material, using the nanowhiskers as growth nucleation sites, thereby to create an epitaxial layer of said second crystalline material extending over said substrate of said first crystalline material.

A method of forming nanowhiskers on a substrate, the method, comprising:

• providing a substrate;
• forming a plurality of catalytic seed particles on a surface of said substrate;
• initially growing nanowhiskers from said catalytic seed particles under first growth conditions that produce nanowhiskers extending from the substrate in a <111> growth direction;
• and
• subsequently changing the <111> growth direction of said nanowhiskers to a <100> direction by growing a short segment of a barrier material in said nanowhiskers, said barrier material being selected to redirect said <111> growth direction to said <100> growth direction.

A method of forming nanowhiskers on a substrate, comprising:

• providing a substrate;
• forming a plurality of catalytic seed particles on a surface of said substrate;
• initially growing nanowhiskers from said catalytic seed particles under first growth conditions that produce nanowhiskers extending from the substrate in a <111> growth direction;
• and
• subsequently changing the <111> growth direction of said nanowhiskers to a <100> direction by changing the first growth conditions to second growth conditions that produce growth of said nanowhiskers in a <100> growth direction.