Infrared-transparent solar cell

Claim 1

A SOLAR CELL OF THE TYPE COMPRISED OF AT LEAST TWO LAYERS OF SEMICONDUCTOR MATERIAL OF OPPOSITE TYPE CONDUCTIVITY DEFINING A P-N JUNCTION, THE SURFACE OF ONE LAYER OPPOSITE SAID P-N JUNCTION BEING SUBSTANTIALLY CLOSER TO SAID P-N JUNCTION THAT THE SURFACE OF SAID OTHER LAYER OPPOSITE SAID P-N JUNCTION, THE SAID SURFACE OF SAID ONE LAYER BEING THE UPPER SURFACE OF SAID SOLAR CELL AND BEIND ADAPTED TO RECEIVE INCIDENT LIGHT, THE SAID SURFACE OF SAID OTHER LAYER BEING THE BOTTOM SURFACE OF SAID SOLAR CELL, SAID UPPER SURFACE HAVING AN ELECTRODE CONFIGURATION THEREON THROUGH WHICH LIGHT CAN PASS TO SAID TOP SURFACE AND INTO SAID SEMICONDUCTOR LAYERS, THE IMPROVEMENT COMPRISING AND ELECYTRODE ON SAID BOTTOM SURFACE FORMED IN A PATTERN OVER SAID SURFACE COVERING LESS THAN 10 PERCENT OF SAID BOTTOM SURFACE, AND A LAYER OF MATERIAL COVERING AT LEAST THOSE PORTIONS OF SAID BOTTOM SURFACE NOT COVERED BY SAID ELECTRODE, SAID LATTER MENTIONED LAYER OF MATERIAL BEING AN ELECTRICAL INSULATOR AND HAVING AN OPTICAL INDEX OF REFRACTION INTERMEDIATE THAT OF THE OPTICAL INDECES OF REFRACTION FOR SAID SEMICONDUCTOR MATERIAL AND SPACE WHEREIN SAID ELECTRODE ON SAID BOTTOM SURFACE PATTERN COMPRISES A PLURALITY OF FINE LINES OF METAL INTERCONNECTED BY OTHER METAL LINES TERMINATING IN LARGER METALLIC AREAS ADAPTED FOR CONNECTING SAID BACK ELECTRODE TO EXTERNAL CIRCUITRY.