Light and electricity
Mar. 13th, 2007 11:35 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
alitalfIn this weeks issue of Electronics Weekly - can't find a web reference - apparently solar cells with an efficiency of just over 40% have been developed. They aren't near to production yet, and they use space grade materials.
The efficiency is gained by using multiple junctions with different bandgaps to absorb different wavelengths. This may well be the only way to make high efficiency solar cells using "conventional" semiconductors, although there may in future be organic approaches that don't need explicit different bandgaps. OTOH chlorophyll isn't that efficient, and rhodopsin is not as efficient as chlorophyll.
A related phenomenon: I noticed a fluctuating reading ont he voltmeter connected to a power supply (under development) that had been switched off for a long while. I noticed a correlation with the sunlight, and found that the LED was generating electricity in response to the sunlight. Of course, the available current is negligible, but it was interesting to observe.
The efficiency is gained by using multiple junctions with different bandgaps to absorb different wavelengths. This may well be the only way to make high efficiency solar cells using "conventional" semiconductors, although there may in future be organic approaches that don't need explicit different bandgaps. OTOH chlorophyll isn't that efficient, and rhodopsin is not as efficient as chlorophyll.
A related phenomenon: I noticed a fluctuating reading ont he voltmeter connected to a power supply (under development) that had been switched off for a long while. I noticed a correlation with the sunlight, and found that the LED was generating electricity in response to the sunlight. Of course, the available current is negligible, but it was interesting to observe.
