Method of manufacturing selenium rectifier cells

Claim 1

IN THE MANUFACTURE OF SELENIUM RECTIFIER CELLS, THE PROCESS OF DEPOSITING, OVER A PERIOD, A LAYER OF AMORPHOUS SELENIUM ON A BASE ELECTRODE, APPLING CRYSTALLITE GROWTHVELOCITY MODIFIER SUBSTANCE TO THE SELENIUM DURING THE PERIOD WITHIN WHICH THE AMORPHOUS SELENIUM IS BEING DEPOSITED, THE SELENIUM DEPOSITION AND THE APPLICATION OF THE MODIFIER SUBSTANCE BEING CARRIED OUT BY VAPORIZING THEM AND PASSING THE VAPORS OVER THE BASE ELECTRODE THE MODIFIER SUBSTANCE BEING VAPORIZED UNDER VACUUM, THE PARTIAL PRESSURE OF THE VAPOR OF THE MODIFIER BEING NOT HIGHER THAN ABOUT 10-2 MM. HG, CONTROLLING THE SUBSEQUENTLY PRODUCED RATE OF GROWTH OF THE CRYSTALLITES ACROSS THE DEPTH OF THE LAYER TO OBTAIN A HIGHER RATE IN THE REGION ADJACENT THE BASE ELECTRODE THAN IN THE PORTION OF THE LAYER MORE REMOTE FROM THE BASE ELECTRODE, THE SAID CONTROL BEING OBTAINED BY CHANGING THE PROPORTION OF THE MODIFIER SUBSTANCE WITH RESPECT TO THE SELENIUM BEING DEPOSITED DURING SAID DEPOSITION PERIOD AND AS THE DEPOSITED LAYER OF SELENIUM INCREASES IN DEPTH, THEREAFTER CRYSTALLIZING THE AMORPHOUS LAYER OF SELENIUM BY HEATING, AND APPLYING A COUNTER ELECTRODE AT THE FACE OF THE RECTIFIER OPPOSITE THE BASE, TO FORM THE CELL.