The practice of this disclosure obtains a relatively high efficiency operation for a crystalline semiconductor solar cell containing various defects of the linear and planar types. Linear defects include screw dislocations as well as full and partial dislocations. Planar defects include twins, stacking faults, grain boundaries and surfaces. Such defects normally contain recombination centers at which electrons and holes generated in the semiconductor region recombine with loss to the external current of the charge carried thereby. Through application of the principles of this invention, especial dopant concentrations and conductivity regions are established in a finite region around the linear and planar defects so that electrons and holes which are generated in the semiconductor region by incident radiation are substantially collected for external current as consequence thereof.