Substrates Used To Grow Zinc Oxide Nanowires

What would be the cost to deposit a thin film of Ti and then a 50nm layer of gold on the 3" silicon wafers and 4" silicon wafers? 

I need these for the growth of ZnO nanowires so the gold layer is critical and must be well adhered to the wafer.

I would like to buy some ZnO crystals in order to replicate at a larger length scale, the work by Wang et al on ZnO as piezoelectric power generators (paper attached).

For this work, they state that their ZnO "nanowires are 'oriented along the c-axis' giving rise to (0001) and (000-1) facets at each end of the nanowire - giving a non-symmetric Schottky contact at one end."

Would it be possible for you to sell me your ZnO crystals, 10 mm x 10 mm x 0.5 mm, but cut into two or three sections so that the crystals are rectilinear?  If so, a quote would be most welcome.

I had a couple questions about the p-GaN on sapphire I purchased. First, which growth method do you use for the layer of p-GaN on the sapphire? Second, and this may be a dumb question, the p-GaN is on the polished side of the substrate correct?

I am trying to grow vertically oriented ZnO nanowires on the p-GaN surface and have been having trouble reproducing previous work so I am trying to learn all I can about the substrates I have been trying to grow on.