Posted by pineappleCoward on June 22, 2008, 12:14 am
Can anyone tell me where to get a few (2-4) wafers for cheap? My only
requirement is that I want both N and P type wafers. Don't care about
size, dopant, orientation, etc. Test grade is fine as long as they
Posted by Eeyore on June 22, 2008, 12:39 am
Hey sunshine, the wafers are SILICON ! PURE SILICON.
You want to dope them, then find a specialist and specify the dopant and
quantity or dope them yourself.
Posted by coj on June 22, 2008, 8:15 am
Most Solar wafers are grown *intentionally doped* at a bulk resistivity
of around 1 ohm.cm (whether multicrystalline, CZ or float zone)
Boron is the dopant used for most p type wafers (the majority of
manufacturers) and Phosphorous can be used for n type (a rarity in Solar
There are process steps (spinning doped layers or diffusions) to add the
emitter layer but these need temperatures up to 1000C to work.
I don't know of anyone who could supply doped wafers with no coating,
the OP might try etching or grinding off any layers already on a solar cell.
What size does the OP need ? What are you going to do with them ?
Posted by Eeyore on June 22, 2008, 11:13 am
Hmmm. Defer. I KNOW a III-IV crystal grower and wafer maker btw. Not especially
relevant nt to this conversation bit I though I'd mention it along with the
flood showers available least you get contaminated with HF.
'Togging up' is fun too after a perverse fashion. Had to do that in a few
I have found Google very useful in these instances.
Posted by coj on June 22, 2008, 9:33 pm
Wafers are doped (or not) depending on what they are going to be used
for. III-V (three five) can be made intrinsic for amplifiers (e.g MMICs)
etc. where they don't want resistive leakage paths between the
components. All solar cells I believe are made on doped bulk material
(although the IC industry would presumably require undoped).
Me too but thankfully not everyday now. It's a pain to do and then
realise you need to nip out again.
I doubt any manufacturers would be interested in requests for a couple
of cells and I think the Chinese seem to be snapping up any excess
available. PV Crystalox make tonnes of Si PV Wafers per year in the UK
and there are a lot of other manufacturers world wide. Maybe the OP
could contact a University that does small scale cell experiments and
may have a couple of spare wafers ?
But consider etching off layers from a cell, I believe Astropower may
have had a whole business once in recycling semiconductor industry wafers.