User talk:Dennis17

I'm an enthusiastic and frequent user of Wikipedia. I'm a very infrequent contributor of minor edits. Every little bit helps.

Dennis17 (talk) 19:34, 8 January 2010 (UTC)


 * I got the limiting figure from this book. I don't have my copy with me, its at the old house, but I seem to recall it starting around page 25. There's a lot of technical papers on the topic you can find on the 'net too, this is a good starting point that discusses the mobility as a function of temperature. Essentially, the limiting factor is due to the speed of the electrons and holes in the bulk side of the cell - if the mobility is low, bright light can saturate production before the electrons can make it to the junction, you can think of a wave of these being emitted when you first turn on a light for instance. After that additional photoelectrons have a high probability of hitting a hole on their way to the junction. Between zero (dark current) and saturation there's a nice production curve you get from stat thermo. Interestingly, if the panel is not directed right at the sun, as in the case of building integrated units, you can exceed any normal limits because the peak sun period is so short for any fixed angle. Basic geometry there, no physics. Maury Markowitz (talk) 21:17, 8 January 2010 (UTC)
 * Actually, the discussion starts around pg 100. Looking into this further, I have found a number of recent references that refer to dramatically higher limits, with one mentioning a 13.6 W/cm^2, about 10000x concentration. Its not clear to me if these are specialized versions though. Maury Markowitz (talk) 16:38, 11 January 2010 (UTC)