Process for thin film deposition of metal and mixed metal chalcogenides displaying semi-conductor properties

Claim 1

A method for producing metal or mixed metal chalcogenide films comprising: providing a substrate for depositing said film thereupon; heating said substrate to a temperature between about 400° C. and 500° C.; providing a solution of at least one salt of a metal selected from the group consisting of iron copper, nickel, cobalt, cadmium, zinc, molybdenum, or mixtures thereof in a mixture of water and a water soluble hydrocarbon; atomizing said solution; contacting said heated substrate with said atomized solution in an oxygen containing ambient to form an adherent film comprising an oxide of said metal or metals; annealing said oxide film at a temperature from about 300° C. to about 400° C. in the presence of a gaseous chalcogen comprising sulfur, selenium, tellurium, or a mixture thereof, capable of undergoing an ion exchange with said oxide film, for a period sufficient to form an adherent film of a chalcogenide compound of said metal or metals.

Claim 2

A method for producing metal or mixed metal chalcogenide films comprising: providing a substrate for depositing said film thereupon; heating said substrate to a temperature between about 400° C. and 500° C.; providing a solution of at least one salt of a metal selected from the group consisting of iron copper, nickel, cobalt, cadmium, zinc, molybdenum, or mixtures thereof in a mixture of water and a water soluble hydrocarbon; atomizing said solution; contacting said heated substrate with said atomized solution in an oxygen containing ambient to form an adherent film comprising an oxide of said metal or metals; annealing said oxide film at a temperature from about 300° C. to about 400° C. in the presence of a gaseous chalcogen comprising sulfur, selenium, tellurium, or a mixture thereof, capable of undergoing an ion exchange with said oxide film, for a period sufficient to form an adherent film of a chalcogenide compound of said metal or metals.

Claim 3

A method for producing metal or mixed metal chalcogenide films comprising: providing a substrate for depositing said film thereupon; heating said substrate to a temperature between about 400° C. and 500° C.; providing a solution of at least one salt of a metal selected from the group consisting of iron, copper, nickel, cobalt, cadmium, zinc, molybdenum, or mixtures thereof in a mixture of water and a water soluble hydrocarbon; atomizing said solution; contacting said heated substrate with said atomized solution in an oxygen containing ambient to form an adherent film comprising an oxide of said metal or metals; annealing said oxide film at a temperature from about 300° C. to about 400° C. in the presence of a protonated gaseous chalcogenide of selenium, tellurium, sulfur or a mixture thereof capable of undergoing an ion exchange with said oxide film, for a time sufficient to form an adherent film of a chalcogenide compound of said metal or metals.

Claim 4

A method for producing metal or mixed metal chalcogenide films comprising: providing a substrate for depositing said film thereupon; heating said substrate to a temperature between about 400° C. and 500° C.; providing a solution of at least one salt of a metal selected from the group consisting of iron, copper, nickel, cobalt, cadmium, zinc, molybdenum, or mixtures thereof in a mixture of water and a water soluble hydrocarbon; atomizing said solution; contacting said heated substrate with said atomized solution in an oxygen containing ambient to form an adherent film comprising an oxide of said metal or metals; annealing said oxide film at a temperature from about 300° C. to about 400° C. in the presence of a protonated gaseous chalcogenide of selenium, tellurium, sulfur or a mixture thereof capable of undergoing an ion exchange with said oxide film, for a time sufficient to form an adherent film of a chalcogenide compound of said metal or metals.

Claim 5

The method set forth in claims 1 or 2 wherein said substrate is maintained at about 475° C.

Claim 6

The method set forth in claims 1 or 2 wherein said annealing time ranges from about 15 minutes to about 60 minutes.

Claim 7

The method set forth in claims 1 or 2 wherein said substrate comprises a metal.

Claim 9

The method set forth in claims 1 or 2 wherein said substrate comprises silicon.

Claim 10

The method set forth in claims 1 or 2 wherein said substrate comprises glass.

Claim 11

The method set forth in claims 1 or 2 wherein said mixture of water and a water soluble hydrocarbon is further characterized as having a hydrocarbon to water ratio from about 90% hydrocarbon, 10% water, to about 50% hydrocarbon, 50% water.

Claim 13

The method set forth in claims 1 or 2 wherein said mixtures comprises 70% methanol by volume.

Claim 14

The method set forth in claims 1 or 2 wherein said contacting is continued for a time sufficient to deposit an oxide film no more than about 10 microns in thickness.

Claim 15

The method set forth in claims 1 or 2 wherein said contacting continues for about 5 minutes to deposit an oxide film which is about 1 micron in thickness.

Claim 16

The method set forth in claims 1 or 2 wherein said metal salt is a nitrate salt.

Claim 19

The method set forth in claims 1 or 2 wherein said solution is further characterized as having a molarity of between about 0.005 to 0.010 molar.

Claim 20

The method set forth in claims 1 or 2 wherein said solution is further characterized as having a molarity of about 0.010 molar.

Claim 21

A method for producing a selective absorbing surface for efficiently converting sunlight energy into heat energy, said method comprising: providing a reflective, thermally conducting substrate for depositing said selective absorbing surface thereupon; heating said substrate to a temperature from about 400° C. to about 500° C.; providing a solution of a nitrate salt of at least one metal selected from iron, copper, cadmium, zinc and nickel dissolved in a mixture of methanol and water; atomizing said solution; contacting said heated substrate with said atomized solution in an oxygen containing ambient to form an adherent film comprising an oxide of said metal or metals; annealing said oxide film at a temperature of about 325° C. for a period of about 30 minutes in the presence of a protonated gaseous chalcogenide of selenium, tellurium, sulfur, or a mixture thereof whereby said oxide film undergoes an ion exchange with said chalcogenide to form an adherent film of a chalcogenide compound of said metal or metals.

Claim 22

A method for producing a selective absorbing surface for efficiently converting sunlight energy into heat energy, said method comprising: providing a reflective, thermally conducting substrate for depositing said selective absorbing surface thereupon; heating said substrate to a temperature from about 400° C. to about 500° C.; providing a solution of a nitrate salt of at least one metal selected from iron, copper, cadmium, zinc and nickel dissolved in a mixture of methanol and water; atomizing said solution; contacting said heated substrate with said atomized solution in an oxygen containing ambient to form an adherent film comprising an oxide of said metal or metals; annealing said oxide film at a temperature of about 325° C. for a period of about 30 minutes in the presence of a protonated gaseous chalcogenide of selenium, tellurium, sulfur, or a mixture thereof whereby said oxide film undergoes an ion exchange with said chalcogenide to form an adherent film of a chalcogenide compound of said metal or metals.

Claim 23

A method for producing a heterojunction photovoltaic device comprising: providing an N-type silicon substrate; heating said substrate to a temperature from about 400° C. to about 500° C.; providing a solution of a nitrate salt or iron and of copper in a mixture of methanol and water; atomizing said solution; contacting said heated substrate with said atomized solution in an oxygen containing ambient for a period of about 5 minutes to form an adherent film comprising an oxide of copper and iron; annealing said oxide film in a gaseous mixture of hydrogen disulfide and nitrogen to form an adherent film comprising Cu 5 FeS 4 whereby a heterojunction is formed between said N-type silicon and said copper iron sulfide.

Claim 24

A method for producing a heterojunction photovoltaic device comprising: providing an N-type silicon substrate; heating said substrate to a temperature from about 400° C. to about 500° C.; providing a solution of a nitrate salt or iron and of copper in a mixture of methanol and water; atomizing said solution; contacting said heated substrate with said atomized solution in an oxygen containing ambient for a period of about 5 minutes to form an adherent film comprising an oxide of copper and iron; annealing said oxide film in a gaseous mixture of hydrogen disulfide and nitrogen to form an adherent film comprising Cu 5 FeS 4 whereby a heterojunction is formed between said N-type silicon and said copper iron sulfide.