New SOLAR CELLS
What is the [in situ] solar cell process?

That is the big breakthrough in solar cell design that drops the cost of solar power to $90 per kilowatt. Actually, the [in situ] (Latin for in place) technique is stunningly simple. Instead of refining the silicon and then building cells, you build the cells first and then refine the silicon.

The process generates a cell from ordinary beach sand (silicon dioxide). After cell fabrication, the sand is chemically treated. The reaction drives off the oxygen, leaving an almost pure polycrystalline silicon. Most conveniently. any remaining impurities rearrange themselves to form uniformly doped series connected p.n. junctions through a process celled Barefoot Layering. For each centimeter of cell thickness, you typically get several hundred series p.n. junctions or about 120 volts dc under normal sunlight. The thickness of the panel determines the voltage and the area the current. Typical current densities are four amperes per square meter of panel!

You can easily build a 100 watt cell. Simply take an ordinary metal cookie sheet, cover it uniformly with a 1 centimeter thick layer of beach sand, cover that with a piece of screening for the front collector, add a protective glass cover, and clamp everything together with large rubber bands, bungee cords, or something similar.

To do your final chemical refinement, carefully remove the glass cover and spray the sand with two liters of 3,7 Dimethylpentadecon-2-ol Propionate (available from larger organic chemical supply houses). [If any body finds a source for this let me know.] An ordinary window cleaner bottle makes a handy spray source. Reaction time is four hours, Since the reaction is photoisentropic It should be done under magenta safe light, such as that from a Portal Industries JJ-668 source.

The front terminal is positive and the greatest output will be obtained when the panel is pointed due south at an elevation of your latitude plus ten degrees. A group of panels can, of course, be wired in parallel for independent, on-site power.

I wrote an email to a local chemical supply asking about the chemical indicated in in this article how to make the solar cell The answer is as below.

Does any know the correct name of the chemical or is this thing a hoax. Any one have any ideas,

Did the article appear in Popular Science and someone got the name wrong.

If it is a hoax its a pity I was willing to give this one a try.

Geoff

Dear Geoff, If the chemical compound you are after is a sex pheromone of the pine sawfly and normally used in picolitre quantities 2 litres would never be affordable.