P and n-type microcrystalline semiconductor alloy material including band gap widening elements, devices utilizing same

Claim 2

An n-doped microcrystalline semiconductor alloy material, said semiconductor alloy material including at least one band gap widening element, said material formed by a random network of relatively low conductivity, disordered regions surrounding highly ordered crystalline inclusions, said volume fraction of crystalline inclusions being greater than a threshold value at which the onset of substantial change in certain key parameters including electrical conductivity and bandgap occurs, whereby the material exhibits substantially increased electrical conductivity and a bandgap of at least aobut 1.9 eV.

Claim 3

A material as in claim 1, wherein the semiconductor is silicon and the n-type dopant is phosphorous.

Claim 4

A material as in claim 2, further including hydrogen.

Claim 5

A material as in claim 3, further including fluorine.

Claim 6

A material as in claim 2, wherein the band gap widening element is selected from the group consisting essentially of nitrogen, carbon, oxygen, and combinations thereof.

Claim 7

A material as in claim 1, characterized by an activation energy of less than approximately 0.05 eV.

Claim 8

A material as in claim 1, characterized by a dark conductivity of greater than 0.5 ohm -1 -cm -1 .

Claim 9

A material as in claim 1, characterized by a band gap of at least approximately 1.9 eV.

Claim 10

A material as in claim 1, characterized by an absorption constant at 5000 angstroms of about 3×10 4 cm -1 .

Claim 11

A material as in claim 1, characterized by a microcrystalline inclusions amounting to at least about 60% in the amorphous network.

Claim 12

In an electronic device of the type which includes at least one set of contiguous p-type and n-type regions of semiconductor alloy material, the improvement comprising, in combination: the n-type semiconductor alloy region of said at least one set including a microcrystalline semiconductor alloy material having at least one band gap widening element incorported into the matrix thereof; said n-type material formed by a random network of relatively low conductivity, disordered regions surrounding highly ordered crystalline inclusions, said volume fraction of crystalline inclusions being greater than a threshold value at which the onset of substantial change in certain key parameters including electrical conductivity and bandgap occurs, whereby the material exhibits substantially increased electrical conductivity and a bandgap of at least about 1.9 eV.

Claim 13

In an electronic device of the type which includes at least one set of contiguous p-type and n-type regions of semiconductor alloy material, the improvement comprising, in combination: the n-type semiconductor alloy region of said at least one set including a microcrystalline semiconductor alloy material having at least one band gap widening element incorported into the matrix thereof; said n-type material formed by a random network of relatively low conductivity, disordered regions surrounding highly ordered crystalline inclusions, said volume fraction of crystalline inclusions being greater than a threshold value at which the onset of substantial change in certain key parameters including electrical conductivity and bandgap occurs, whereby the material exhibits substantially increased electrical conductivity and a bandgap of at least about 1.9 eV.

Claim 14

A device as in claim 11, wherein the semiconductor is silicon and the n-type region includes phosphorous.

Claim 15

A device as in claim 12, wherein the n-type region further includes hydrogen and fluorine.

Claim 16

A device as in claim 11, wherein the band gap widening element is selected from the group consisting essentially of nitrogen, carbon, oxygen, and combinations thereof.

Claim 17

A device as in claim 11, wherein the n-type region is characterized by an activation energy of less than approximately 0.05 eV, a band gap of at least approximately 2.0 eV and a dark conductivity of greater than about 0.5 ohms -1 cm -1 .

Claim 18

In a photovoltaic device of the type which includes at least two superposed cells, each cell including a layer of n-type semiconductor alloy material, the improvement comprising: the n-type layer of each of the cells formed of an n-type microcrystalline semiconductor alloy material, said material including at least one band gap widening element; said n-type material formed by a random network of relatively low conductivity, disordered regions surrounding highly ordered crystalline inclusions, said volume fraction of crystalline inclusions being greater than a threshold value at which the onset of substantial change in certain key parameters including electrical conductivity and bandgap occurs, whereby the material exhibits substantially increased electrical conductivity and a band gap of at least about 1.9 eV.

Claim 19

In a photovoltaic device of the type which includes at least two superposed cells, each cell including a layer of n-type semiconductor alloy material, the improvement comprising: the n-type layer of each of the cells formed of an n-type microcrystalline semiconductor alloy material, said material including at least one band gap widening element; said n-type material formed by a random network of relatively low conductivity, disordered regions surrounding highly ordered crystalline inclusions, said volume fraction of crystalline inclusions being greater than a threshold value at which the onset of substantial change in certain key parameters including electrical conductivity and bandgap occurs, whereby the material exhibits substantially increased electrical conductivity and a band gap of at least about 1.9 eV.

Claim 20

A photovoltaic device as in claim 16, wherein said n-type microcrystalline semiconductor alloy material is a silicon alloy and the n-dopant is phosphorous.

Claim 21

A photovoltaic device as in claim 17, wherein said n-type microcrystalline semiconductor alloy material further includes hydrogen and fluorine.

Claim 22

A photovoltaic device as in claim 16, wherein said band gap widening element is selected from the group consisting essentially of nitrogen, carbon, oxygen, and combinations thereof.

Claim 23

A photovoltaic device as in claim 19, wherein said n-type microcrystalline semiconductor alloy material includes microcrystalline inclusions amounting to at least about 70% in the amorphous network.

Claim 24

A photovoltaic device as in claim 16, wherein each cell of the photovoltaic device also includes a p-type microcrystalline semiconductor alloy material.

Claim 25

A photovoltaic device as in claim 21, wherein the p-type microcrystalline semiconductor alloy material includes a band gap widening element selected from the group consisting essentially of nitrogen, carbon, and combinations thereof.

Claim 26

In a single photovoltaic cell, said cell including a layer of n-type semiconductor alloy material, a layer of substantially intrinsic semiconductor alloy material and a layer of p-type semiconductor alloy material; the improvement comprising, in combination: the n-type layer and the p-type layers being microcrystalline and including at least one band gap widening element in each of the host matrixes thereof, said widening element selected from the group consisting essentially of nitrogen, carbon, oxygen, and combinations thereof; the n-type and p-type materials formed by a random network of relatively low conductivity, disordered regions surrounding highly ordered crystalline inclusions, said volume fraction of crystalline inclusions being greater than a threshold value at which the onset of substantial change in certain key parameters including electrical conductivity and bandgap occurs, whereby the material exhibits substantially increased electrical conductivity and a bandgap of at least about 1.9 eV.

Claim 27

In a single photovoltaic cell, said cell including a layer of n-type semiconductor alloy material, a layer of substantially intrinsic semiconductor alloy material and a layer of p-type semiconductor alloy material; the improvement comprising, in combination: the n-type layer and the p-type layers being microcrystalline and including at least one band gap widening element in each of the host matrixes thereof, said widening element selected from the group consisting essentially of nitrogen, carbon, oxygen, and combinations thereof; the n-type and p-type materials formed by a random network of relatively low conductivity, disordered regions surrounding highly ordered crystalline inclusions, said volume fraction of crystalline inclusions being greater than a threshold value at which the onset of substantial change in certain key parameters including electrical conductivity and bandgap occurs, whereby the material exhibits substantially increased electrical conductivity and a bandgap of at least about 1.9 eV.

Claim 28

A photovoltaic cell in claim 23, wherein said microcrystalline semiconductor alloy material is silicon, the p-dopant is boron and the n-dopant is phosphorous.

Claim 29

A photovoltaic cell as in claim 24, wherein said microcrystalline semiconductor alloy materials of the n-type and p-type layers further include hydrogen.

Claim 30

A photovoltaic cell as in claim 25, wherein the band gap widening element of the n-type layer is nitrogen and the band gap widening element of the p-type layer is carbon.

Claim 31

A photovoltaic cell as in claim 25, wherein the n-type and p-type layers of semiconductor alloy material further include fluorine.

Claim 32

A photovoltaic cell as in claim 23, wherein said n-type and p-type layers of microcrystalline semiconductor alloy material are characterized by an activation energy of less than approximately 0.05 eV.

Claim 33

A photovoltaic cell as in claim 23, wherein said p-type layer of microcrystalline semiconductor alloy material is characterized by a band gap of at least approximately 2.1 eV and said n-type layer of semiconductor alloy material is characterized by a band gap of at least approximately 2.0 eV.

Claim 34

A photovoltaic cell as in claim 23, further including a dual layered back reflector below the n-type layer and an anti-reflection transparent conductive oxide atop the p-type layer.

Claim 35

A photovoltaic cell as in claim 30, wherein said back reflector includes a zinc oxide layer sandwiched between said n-type layer and a highly reflective layer.

Claim 36

A photovoltaic cell as in claim 31, wherein said highly reflective layer includes a material selected from the group consisting essentially of gold, silver and copper.