2 NEW TYPES OF GRADED-BAND-GAP SOLAR-CELLS

Two new types of graded-band-gap solar cells are suggested and studied theoretically in order to find out their current-voltage characterist ics and limiting ideal efficiencies. In the first one the photo-magnet o-voltaic effect is used for the separation of photocarriers. An analy ses of solar cell has shown that its ideal efficiency goes to the ther modynamic limit, provided modulus of non-diagonal magneto-conductiviti es for holes and electrons are equal and the amplitude of the external magnetic field is high enough H much greater than mc/etau, where m an d tau are mass and scattering time of carriers. This type of solar cel l is mainly interesting from a theoretical point of view, but seems to be far from a practical application because it needs to use a high ma gnetic field. The second type of solar cell uses a wire-doping of a sp ecial kind for the photocarrier separation. The work of this solar cel l is quite similar to the previous one, and it is shown that the wire doping can be successfully used instead of the external magnetic field without any losses in efficiency. This type of graded-band-gap solar cell may be of practical interest, provided a way for the production o f wire doping can be found.