Chalcogenide absorber layers for photovoltaic applications and methods of manufacturing the same

Abstract

In one example embodiment, a method includes depositing one or more thin-film layers onto a substrate. More particularly, at least one of the thin-film layers comprises at least one electropositive material and at least one of the thin-film layers comprises at least one chalcogen material suitable for forming a chalcogenide material with the electropositive material. The method further includes annealing the one or more deposited thin-film layers at an average heating rate of or exceeding 1 degree Celsius per second. The method may also include cooling the annealed one or more thin-film layers at an average cooling rate of or exceeding 0.1 degrees Celsius per second.

What is claimed is: 
     
         1 . A multi layer structure comprising:
 a film layer comprising Cu α (In 1-x Ga x ) β  (where α>β, 0≦x≦1) and one or more of Se, Te, or S that is annealed at an average heating rate of at least approximately 1 degree Celsius per second and cooled after removal of excess material including Cu and one or more of S, Se, or Te at an average cooling rate of at least approximately 0.1 degrees Celsius per second.   
     
     
         2 . The multi layer structure of  claim 1  comprising [Cu/In 1-x Ga x ] N /Se 1-y-z S y Te z  (where x≦0.7, 0≦y≦1, 0≦z≦1, N≦100). 
     
     
         3 . The multi layer structure of  claim 2  wherein at least one layer of the multilayer structure comprises up to approximately 20 atomic % of at least one of the following elements: Al, Si, Ti, V, Zn, Ga, Zr, Nb, Mo, Ru, Pd, In, Sn, Ta, W, Re, Ir, Pt, Au, Pb, or Bi. 
     
     
         4 . The multi layer structure of  claim 2  wherein at least one layer of the multilayer structure comprises [Cu α (In 1-x Ga x ) β (Se 1-y-z S y Te z ) 1-α-β ], (where for each layer 0≦α≦1, 0≦β1, x≦0.7, 0≦y≦1, 0≦z≦1, and total concentration of Cu, In and Ga, and Se+S+Te of the film layer does not exceed 30 atomic %, 30 atomic %, and 70 atomic %, respectively. 
     
     
         5 . The multi layer structure of  claim 1  wherein the film layer is a multilayer structure comprising [(In 1-x Ga x ) 1-α (Se 1-y-z S y Te z ) α (/Cu 1-β (Se 1-y-z S y Te z ) β ] N  (where x α0.7, α≦0.8, β≦0.8, 0≦y≦1, 0≦z≦1, N≦100). 
     
     
         6 . The multi layer structure of  claim 1  wherein the film layer comprises Cu α (In 1-x Ga x ) β (Se 1-y-z S y Te z ) 1-α-β  (where 0.1≦α≦0.4, 0.1≦β≦0.4, α+β≦0.7, 0≦y≦1, 0≦z≦1). 
     
     
         7 . The multi layer structure of  claim 6  wherein, for 0.5<α+β≦0.7, the film layer is annealed in the presence of H 2 S, H 2 Se, or both. 
     
     
         8 . The multi layer structure of  claim 1  wherein the film layer is doped with at least one of the following elements: Na, P, K, N, B, As, or Sb. 
     
     
         9 . The multi layer structure of  claim 1  wherein the film layer has a thickness of 0.15 to 8.0 μm. 
     
     
         10 . The multi layer structure of  claim 1  wherein the film layer comprises In 1-x CU x  (where x>0.5). 
     
     
         11 . The multi layer structure of  claim 1  wherein annealing the film layer results in the formation of Cu(In, Ga)(S, Se, Te) 2  with a tetragonal chalcopyrite crystal structure. 
     
     
         12 . The multi layer structure of  claim 1  wherein the excess material comprises CU 1-x S x  (where 0.2≦x≦1). 
     
     
         13 . The multi layer structure of  claim 1  wherein the excess material comprises CU 1-x Se x  (where 0.2≦x≦1). 
     
     
         14 . The multi layer structure of  claim 1  wherein the excess material comprises CU 1-x (S, Se) x  (where 0.2≦x≦1). 
     
     
         15 . The multi layer structure of  claim 1  wherein the excess material comprises CU 1-x (S, Se, Te) x  (where 0.2≦x≦1). 
     
     
         16 . The multi layer structure of  claim 1  wherein the excess material comprises CU 1-x (Se 1-y S y Te z ) x  (where 0.1≦x≦1, 0≦y≦1, 0≦z≦1). 
     
     
         17 . The multi layer structure of  claim 1 , further comprising:
 an underlying layer on a substrate, the underlying layer comprising CU m (In 1-k Ga k ) n  (where 0≦k≦1) and one or more of Se, Te, or S, wherein the film layer is deposited onto the underlying layer.   
     
     
         18 . The multi layer structure of  claim 1 , further comprising:
 an overlying layer on the film layer, the overlying layer comprising CU m (In 1-k Ga k ) n  (where 0≦k≦1) and one or more of Se, Te, or S;   wherein the film layer and overlying layer are annealed at an average heating rate of at least approximately 1 degree Celsius per second.   
     
     
         19 . The multi layer structure of  claim 19 , where n>m. 
     
     
         20 . The multi layer structure of  claim 1 , further comprising:
 an underlying layer on a substrate, the underlying layer comprising CU m (In 1-k Ga k ) n  (where 0≦k≦1) and one or more of Se, Te, or S, wherein the film layer is deposited onto the underlying layer; and   an overlying layer on the film layer, the overlying layer comprising Cu q (In 1-k Ga k ) r  (where 0≦p≦1) and one or more of Se, Te, or S.