Optimized Design of Direct Gap Photovoltaic Cells

Once the photovoltaically active semiconductor has been selected for a solar cell, the objective of the solar cell designer is to extract as much efficiency as possible from a cell made of that material. Since some of the elements used in the A and 

Expressions for the reverse saturation current I are calculated from the ambipolar diffusion equation which governs the transport of the thermally generated minority carriers in the homogeneous, quasi-neutral regions of the cell. For the one dimensional case, this equation has the form 

The metallurgical junction -P are the coordinates of the edges of the space charge region. 

The surfaces of these homogeneous regions farthest from the junction (at A and B in Fig. 11 ) are commonly characterized by surface recombination velocities S for the surface of the cell on which light is incident and S ror the back surface of the cell. This translates into the boundary condition 

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