Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
148 words
A method for forming a photovoltaic transducer including a substrate, a contact on the substrate, a first semiconductor layer deposited on the contact, and a second semiconductor layer deposited on the first layer, the layers defining thin-film heterojunction, the method comprising the steps of: (a) forming the first layer of I―III―VI 2 , chalcopyrite material by.simultaneous elemental evaporation, the layer having a low-resistivity, A-type region enriched in the I material and a high-resistivity, B-type region deficient in the I material, the two regions being sequentially formed one upon the other and defining a transient homojunction; and (b) forming the second layer of B-type semiconductor material by depositing a II―VI material on the high resistivity region while permitting interdiffusion within the first layer to convert the high-resistivity region from B-type to A-type, thereby defining a thin-film heterojunction, wherein A-type=n-type or p-type and B-type=p-type, if A-type=n-type; or n-type if A-type=p-type.
Claim 2
Independent Claim
148 words
A method for forming a photovoltaic transducer including a substrate, a contact on the substrate, a first semiconductor layer deposited on the contact, and a second semiconductor layer deposited on the first layer, the layers defining thin-film heterojunction, the method comprising the steps of: (a) forming the first layer of I―III―VI 2 , chalcopyrite material by.simultaneous elemental evaporation, the layer having a low-resistivity, A-type region enriched in the I material and a high-resistivity, B-type region deficient in the I material, the two regions being sequentially formed one upon the other and defining a transient homojunction; and (b) forming the second layer of B-type semiconductor material by depositing a II―VI material on the high resistivity region while permitting interdiffusion within the first layer to convert the high-resistivity region from B-type to A-type, thereby defining a thin-film heterojunction, wherein A-type=n-type or p-type and B-type=p-type, if A-type=n-type; or n-type if A-type=p-type.
Claim 3
Dependent Claim
38 words
the method of claim 1 wherein the I―III―VI 2 chalcopyrite material is CulnSe 2 , and wherein the II-VI material is selected from the group consisting of: CdS; Cd 1-x Zn x S; and CdS 1-x Se x
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein the low resistivity region is p-type.
Claim 5
Dependent Claim
15 words
The method of claim 1 further comprising heating the transducer following depositing the second layer.
Claim 6
Dependent Claim
11 words
The method of claim 2 wherein the II-VI material is CdS.
Claim 7
Dependent Claim
66 words
A photovoltaic transducer produced according to the method of claim 1 or 4 comprising: (a) a first semiconductor layer of I―III―VI 2 chalcopyrite material having a low resistivity region enriched in the I material and a high resistivity region deficient in the I material; and (b) a second semiconductor layer of II-VI material in face-to-face contact with the high resistivity region to define a thin-film heterojunction.
Claim 8
Dependent Claim
20 words
The transducer of claim 6 wherein the I―III―VI 2 chalcopyrite material is CuInSe 2 and the II-VI material is CdS.
Claim 9
Dependent Claim
26 words
The transducer of claim 7 wherein the first region is p-type, the second region is n-type that evolves into p-type, and the second layer is n-type.
Claim 10
Dependent Claim
139 words
An apparatus for forming a photovoltaic transducer according to the method of claim 1 comprising a thin-film heterojunction including a substrate, a ternary material on the substrate, and a semiconductor material on the ternary material, the apparatus comprising: (a) means for forming a low resistivity base metal contact on the substrate; (b) means for forming a transient p-n-type thin film homojunction of a l―lll―Vl 2 chalcopyrite material on the contact by simultaneous elemental evaporation of the constituent elements; (c) means for monitoring and controlling the co-evaporation of the I and III materials, the control means using electron impact emission spectroscopy for monitoring the ratio of the 1:111 materials and thereby controlling the composition of the transient homojunction and permitting the formation of a first region enriched in the I material and a second region deficient in the I material.
Claim 11
Dependent Claim
21 words
The apparatus of claim 9 further comprising means for maintaining the substrate at a temperature in the range of about 350-500°C.