Multilayer structure to form absorber layers for solar cells
View Patent ↗A method of forming a doped Group IBIIIAVIA absorber layer for solar cells by reacting a partially reacted precursor layer with a dopant structure. The precursor layer including Group IB, Group IIIA and Group VIA materials such as Cu, Ga, In and Se are deposited on a base and partially reacted. After the dopant structure is formed on the partially reacted precursor layer, the dopant structure and partially reacted precursor layer is fully reacted. The dopant structure includes a dopant material such as Na.
1. A multilayer structure to form absorber layers for solar cells, comprising:
a base comprising a substrate layer;
a partially reacted precursor layer formed on the base, wherein the partially reacted precursor layer comprises at least one of a Group IB-VIA non-metallic phase or a Group IIIA-VIA non-metallic phase; and
a dopant layer on the partially reacted precursor layer, wherein the dopant layer includes a Group IA material.
2. The multilayer structure of claim 1 , wherein the Group IB material is Cu, Group IIIA material is at least one of In or Ga, Group VIA material is at least one of Se or S, and Group IA material includes one of Na, K or Li.
3. The multilayer structure of claim 2 , wherein the partially reacted precursor layer further comprises at least one of the metallic phases of Cu, In, Ga, Cu—In alloy, In—Ga alloy, Cu—Ga alloy and Cu—In—Ga alloy.
4. The multilayer structure of claim 2 , wherein the partially reacted precursor layer further comprises a non-metallic phase selected from the group of CuIn-selenide/sulfide, and CuGa-selenide/sulfide, CuInGa-selenide/sulfide.
5. The multilayer structure of claim 3 , wherein the partially reacted precursor layer further comprises a non-metallic phase selected from the group of CuIn-selenide/sulfide, and CuGa-selenide/sulfide, CuInGa-selenide/sulfide.
6. The multilayer structure of claim 3 wherein the metallic phase constitutes less than 50% of the chemical composition of the partially reacted precursor layer.
7. The multilayer structure of claim 5 wherein the metallic phase constitutes less than 50% of the chemical composition of the partially reacted precursor layer.
8. The multilayer structure of claim 2 , wherein the dopant layer has a thickness of 2-100 nm.
9. The multilayer structure of claim 2 , wherein the substrate layer is a stainless steel web.
10. The multilayer structure of claim 9 , wherein the base further comprises a contact layer including one of Mo, W, Ru, Ir or Os.