Photo-emissive device including emitter and insulator of less than mean free path dimensions

Claim 1

A PHOTOVOLTAIC DEVICE FOR CONVERTING INCIDENT LIGHT TO ELECTRICAL ENERGY, COMPRISING, IN COMBINATION: A FIRST PHOTOABSORPTIVE, PHOTOEMISSIVE, AND ELECTRICALLYY CONTINUOUS CONDUCTIVE LAYER COMPRISING A FILM OF METAL HAVING A THICKNESS OF ABOUT 50 TO 300 ANGSTORMS AND LESS THAN THE MEAN FREE PATH FOR ELECTRONS IN SAID METAL, WHEREBY INCIDENT LIGHT WILL GENERATE FREE ELECTRONS IN SAID FILM YET SAID FILM WILL BE THICK ENOUGH TO BE MECHANICALLY STABLE AND ELECTRICALLY CONTINUOUS, ONE SURFACE OF SAID LAYER BEING EXPOSED SO THAT LIGHT CAN BE RECEIVED SUBSTANTIALLY DIRECTLY THEREON, A LAYER OF INSULATING MATERIAL ADJACENT SAID FIRST LAYER, SAID INSULATING LAYER HAVING A THICKNESS OF ABOUT 70 TO 100 ANGSTROMS AND LESS THAN THE MEAN FREE PATH FOR ELECTRONS IN SAID INSULATING MATERIAL, WHEREBY SAID INSULATING LAYER WILL HAVE AN EFFECTIVE REVERSE RESISTANCE OF GREATER THAN 10**6 OHMS PER SQUARE CENTIMETER FOR AN APPLIED POTENTIAL DIFFERENCE THEREACROSS OF ONE VOLT, AND WHEREBY FREE ELECTRONS GENERATED IN SAID FIRST LAYER WILL BE ABLE TO PASS THROUGH SAID INSULATING LAYER, A CONDUCTIVE COLLECTOR LAYER OF A MATERIAL DIFFERENT FROM THE METAL FILM OF SAID FIRST LAYER AND ADJACENT THE OTHER SIDE OF SAID INSULATING LAYER, SAID COLLECTOR LAYER HAVING A THICKNESS OF ABOUT 1000 ANGSTROMS OR GREATER, WHEREBY SAID COLLECTOR LAYER WILL REFLECT RATHER THAN ABSORB MOST OF THE RESIDUAL LIGHT REACHING IT THROUGH SAID FIRST AND SAID INSULATING LAYERS, AND MEANS FOR PROVIDING RESPECTIVE ELECTRICAL CONNECTIONS TO SAID COLLECTOR LAYER AND SAID FIRST LAYER TO WHICH A LOAD IMPEDANCE MAY BE CONNECTED, SAID FIRST CONDUCTIVE LAYER AND SAID COLLECTOR LAYER BEING INSULATED FROM EACH OTHER.