Betavoltaics

A proposed for a long-lasting power source operating principle was Betavoltaik, named after the beta radiation, ie, high-energy electrons from radioactive decay, generated by collision processes in the pn junction of a semiconductor numerous secondary charge carriers, which then, as in the PV by the space charge zone against a external voltage to be separated, so that electrical power can be removed.

Demonstrated over 50 years ago, the idea was taken up from time to time. Even with alpha emitters were experimented. The problem has always been the low efficiency. Neither the search for new materials (larger band gap, lower radiation damage), nor the enlargement of the semiconductor surface by surface structuring (porous silicon ) gave satisfactory results. Hardly successful was the detour via photons by means of scintillators. Last durable energy sources were all candidates of this type excluded prematurely in a comparative study of NASA suitability, because this principle foreseeable can not get beyond the milliwatt range.

Itemization

• Radionuclide
• Battery Technology
• Photovoltaic