From: John Woodgate
Subject: Re: Galena solar panels?
Date: Tue, 8 Oct 2002 09:31:20 +0100
Organization: JMWA Electronics Consultancy
Reply-To: John Woodgate
NNTP-Posting-Date: Tue, 8 Oct 2002 10:20:01 +0000 (UTC)
X-Newsreader: Turnpike (32) Version 4.01 <5Z8C9wtxbnpWyFnyfFzqmVF739>
I read in sci.electronics.design that Glen Walpert
wrote (in ) about 'Galena
solar panels?', on Tue, 8 Oct 2002:
>In article <0e74BlBZrco9Ewqz@jmwa.demon.co.uk>, John Woodgate
>>Interesting. Galena is lead sulfide and Philips used lead sulfide as a
>>very low light level photoelectric material in their 'Plumbicon' vidicon
>>tubes. I went to a demo where they obtained usable pictures in a large
>>auditorium illuminated by one small wax candle.
>Interesting, indeed. I tried to find a description of how the Plumbicon
IIRC, it's almost a vidicon with a PbS target.
>but all I could find was history of Plumbicons in TV broadcasting and
>where to buy new Plumbicons for medical X-ray imaging, and a mention of a
>bandgap of .41 eV @ 300 K for Galena (corresponding to 3026 nm photon energy),
>compared to 1.1 eV for Silicon (1128 nm photon energy). So although lower
>energy photons can excite an electron in Galena than in Silicon, the excess
>photon energy above the bandgap is lost, and, all other things being equal,
>Silicon solar cells should be 268% more efficient than Galena solar cells when
>operated on light more energetic than 1128 nm (which is near infrared).
No doubt the infra-red from the candle was responsible for most of the
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
PLEASE do NOT copy news posts to me by E-MAIL!