When I first started playing with scrap solar cells I was immediately taken by the blue crystalline pattern of the polycrystalline cells. I thought they would visually mix well with other materials like aluminum, stainless, and bamboo. I used to buy small packages of re-claimed damaged cells on eBay; ones that had been re-cut by diamond blade to about 4cm x 7cm. I remember there being only a few sellers that had raw solar cells like this. This was probably around 2002-2003. Now if you look on ebay today and search for solar cells you will find many, many different sellers with all varieties of raw solar cells. Latest prices for polycrystalline cells are about .50 cents per Watt or 70 W for $18.
There are many suppliers in China offering epoxy encapsulated small solar panels, in the 5v .25-5W range. These panels are quite nice on first glance, but my experiments with this product have proven that the epoxy is of poor quality and quickly degrades to a dull, flat, milky yet still translucent color. I have seen these panels degrade after only six months of outdoor exposure.
Thin film is also ubiquitous on eBay with many suppliers in the Philippines and Malaysia offering encapsulated thin film modules for around $6 for a 2V 1W panel.
Powerfilm is a quality product for thin film modules and available in many sizes for customizable pv forms. Of all the suppliers, Powerfilm is a little more expensive at around $20 USD per Watt. As a side note: I was surprised to find a link to Careford Scientific which offers a 2kW shade structure that uses Powerfilm for $82k USD! A bit pricey for most consumers, but nevertheless an interesting full-scale application of thin film into a deployable shade structure.
Infinity PV is a Danish startup using Kickstarter to fund their HeLi-on solar charger. This is an exciting implementation of organic thin-film in a portable charger application. At a price of around $100 this charger can charge the average smartphone in just 2-3 hours!
Sun power Maxeon cells are a newer product that looks promising for custom pv modules since they are made of copper and are flexible. At $10 USD for 10 pcs of 3.5W each 125x125mm cells, these may be the cheapest flexible material available today. Again, these cells are raw and must be encapsulated somehow to protect from water and environmental damgage.
With all of these options it is clear that the market has greatly expanded over the past ten years to have a wide variety of pv materials readily available for people to explore whether in artistic or practical applications!