Abstract: Methods are described for forming CIGS absorber layers in TFPV devices with graded compositions and graded band gaps. Methods are described for utilizing Al to increase the band gap at the front surface of the absorber layer. Methods are described for forming a Cu—In—Ga layer followed by partial or full selenization. This results in a higher Ga concentration at the back interface. The substrate is then exposed to an aluminum CVD precursor while the substrate is still in the selenization equipment to deposit a thin Al layer. The substrate is then exposed to a Se source to fully convert the absorber layer. This results in a higher Al concentration at the front of the absorber.

Abstract: Methods are described for forming CIGS absorber layers in TFPV devices with graded compositions and graded band gaps. Methods are described for utilizing Ag to increase the band gap at the front surface of the absorber layer. Methods are described for utilizing Al to increase the band gap at the front surface of the absorber layer. Methods are described for utilizing at least one of Na, Mg, K, or Ca to increase the band gap at the front surface of the absorber layer.

Abstract: Methods of forming CZTS absorber layers in a TFPV device with a graded bandgap with or without a graded concentration are provided. In general, a Cu—Zn—Sn—(S, Se) precursor film is formed by sputtering. The Cu—Zn—Sn—(S, Se) precursor film can be formed as a single layer or as a multilayer stack. The composition may be uniform or graded throughout the thickness of the film. In some embodiments, the sputtering is performed in a reactive atmosphere including a chalcogen source (e.g. H2S, H2Se, etc.). The films, in conjunction with a subsequent selenization or anneal process, are converted to an absorber layer.

Abstract: Methods are described for forming CIGS absorber layers in TFPV devices with graded compositions and graded band gaps. Methods are described for utilizing Al to increase the band gap at the front surface of the absorber layer. Methods are described for forming a Cu—In—Ga layer followed by partial or full selenization. This results in a higher Ga concentration at the back interface. The substrate is then exposed to an aluminum CVD precursor while the substrate is still in the selenization equipment to deposit a thin Al layer. The substrate is then exposed to a Se source to fully convert the absorber layer. This results in a higher Al concentration at the front of the absorber.

Abstract: A method for fabricating high efficiency CIGS solar cells including the deposition of Ga concentrations (Ga/(Ga+In)=0.25?0.66) from sputtering targets containing Ga concentrations between about 25 atomic % and about 66 atomic %. Further, the method includes a high temperature selenization process integrated with a high temperature anneal process that results in high efficiency.

Abstract: A method for forming copper indium gallium (sulfide) selenide (CIGS) solar cells, cadmium telluride (CdTe) solar cells, and copper zinc tin (sulfide) selenide (CZTS) solar cells using laser annealing techniques to anneal the absorber and/or the buffer layers. Laser annealing may result in better crystallinity, lower surface roughness, larger grain size, better compositional homogeneity, a decrease in recombination centers, and increased densification. Additionally, laser annealing may result in the formation of non-equilibrium phases with beneficial results.

Abstract: Methods are described for forming CIGS absorber layers in TFPV devices with graded compositions and graded band gaps. Methods are described for utilizing Ag to increase the band gap at the front surface of the absorber layer. Methods are described for utilizing Al to increase the band gap at the front surface of the absorber layer. Methods are described for utilizing at least one of Na, Mg, K, or Ca to increase the band gap at the front surface of the absorber layer.

Abstract: A method for fabricating high efficiency CIGS solar cells including the deposition of Ga concentrations (Ga/(Ga+In)=0.25?0.66) from sputtering targets containing Ga concentrations between about 25 atomic % and about 66 atomic %. Further, the method includes a high temperature selenization process integrated with a high temperature anneal process that results in high efficiency.

Abstract: A method for fabricating high efficiency CIGS solar cells including the deposition of Ga concentrations (Ga/(Ga+In)=0.25?0.66) from sputtering targets containing Ga concentrations between about 25 atomic % and about 66 atomic %. Further, the method includes a high temperature selenization process integrated with a high temperature anneal process that results in high efficiency.

Abstract: A method for fabricating high efficiency CIGS solar cells including the deposition of Ga concentrations (Ga/(Ga+In)=0.25-0.66) from sputtering targets containing Ga concentrations between about 25 atomic % and about 66 atomic %. Further, the method includes a high temperature selenization process integrated with a high temperature anneal process that results in high efficiency.

Abstract: A method for fabricating high efficiency CIGS solar cells including the deposition of Ga concentrations (Ga/(Ga+In)=0.25?0.66) from sputtering targets containing Ga concentrations between about 25 atomic % and about 66 atomic %. Further, the method includes a high temperature selenization process integrated with a high temperature anneal process that results in high efficiency.

Abstract: A method for high temperature selenization of Cu—In—Ga metal precursor films comprises ramping the precursor film to a temperature between about 350 C and about 450 C in an inert gas and at a pressure between about 1 atmosphere and about 2 atmospheres. A partial selenization is performed at a temperature between about 350 C and about 450 C in a Se-containing atmosphere. The film is then ramped to a temperature between about 450 C and about 550 C in an inert gas and at a pressure between about 1 atmosphere and about 2 atmospheres, followed by an additional selenization step at a temperature between about 450 C and about 550 C in a Se-containing atmosphere. The film is then annealed at a temperature between about 550 C and about 650 C in an inert gas.

Abstract: A method for forming copper indium gallium (sulfide) selenide (CIGS) solar cells, cadmium telluride (CdTe) solar cells, and copper zinc tin (sulfide) selenide (CZTS) solar cells using laser annealing techniques to anneal the absorber and/or the buffer layers. Laser annealing may result in better crystallinity, lower surface roughness, larger grain size, better compositional homogeneity, a decrease in recombination centers, and increased densification. Additionally, laser annealing may result in the formation of non-equilibrium phases with beneficial results.

Abstract: Methods are described for forming CIGS absorber layers in TFPV devices with graded compositions and graded band gaps. Methods are described for utilizing Ag to increase the band gap at the front surface of the absorber layer. Methods are described for utilizing Al to increase the band gap at the front surface of the absorber layer. Methods are described for utilizing metal chalcogenide layers to impact the band gap and the morphology of the absorber layer.

Abstract: Methods are described for forming CIGS absorber layers in TFPV devices with graded compositions and graded band gaps. Methods are described for depositing a Cu-rich precursor layer followed by a Cu-poor precursor layer. Methods are described for depositing a Cu-poor precursor layer followed by a Cu-rich precursor layer. Methods are described for depositing a Cu-poor precursor layer followed by a Cu-poor precursor layer. Methods are described for depositing a Cu-rich precursor layer followed by removing excess Cu-chalcogenide using a wet etch, followed by a Cu-poor precursor layer. Methods are described for utilizing Ag to increase the band gap at the front surface of the absorber layer. Methods are described for utilizing Al to increase the band gap at the front surface of the absorber layer.

Abstract: Methods are described for forming CZTS absorber layers in TFPV devices with graded compositions and graded bandgaps. Methods are described for utilizing at least one of Zn, Ge, or Ag to alter the bandgap within the absorber layer. Methods are described for utilizing Te, S, Se, O, Cd, Hg, or Sn to alter the bandgap within the absorber layer. Methods are described for utilizing either a 2-step process or a 4-step process to alter the bandgap within the absorber layer.

Abstract: Methods are described for forming CIGS absorber layers in TFPV devices with graded compositions and graded band gaps. Methods are described for utilizing Ag to increase the band gap at the front surface of the absorber layer. Methods are described for utilizing Al to increase the band gap at the front surface of the absorber layer. Methods are described for utilizing at least one of Na, Mg, K, or Ca to increase the band gap at the front surface of the absorber layer.

Abstract: Methods for increasing the power output of a TFPV solar panel using thin absorber layers comprise techniques for roughening and/or texturing the back contact layer. The techniques comprise roughening the substrate prior to the back contact deposition, embedding particles in sol-gel films formed on the substrate, and forming multicomponent, polycrystalline films that result in a roughened surface after a wet etch step, etc.

Abstract: Methods and compositions for forming porous low refractive index coatings on substrates are provided. The method comprises coating a substrate with a sol-formulation comprising silica based nanoparticles and an alkyltrialkoxysilane based binder. Use of the alkyltrialkoxysilane based binder results in a porous low refractive index coating having bimodal pore distribution including mesopores formed from particle packing and micropores formed from the burning off of organics including the alkyl chain covalently bonded to the silicon. The mass ratio of binder to particles may vary from 0.1 to 20. Porous coatings formed according to the embodiments described herein demonstrate good optical properties (e.g. a low refractive index) while maintaining good mechanical durability due to the presence of a high amount of binder and a close pore structure.

Abstract: Method for forming back contact stacks for CIGS and CZTS TFPV solar cells are described wherein some embodiments include adhesion promoter layers, bulk current transport layers, stress management/diffusion barrier layers, optical reflector layers, and ohmic contact layers. Other back contact stacks include adhesion promoter layers, bulk current transport layers, diffusion barrier layers, and ohmic contact layers.