title: Quantum efficiency and bandgap analysis for combinatorial photovoltaics: sorting activity of Cu-O compounds in all-oxide device libraries.
abstract: All-oxide-based photovoltaics (PVs) encompass the potential for extremely low cost solar cells, provided they can obtain an order of magnitude improvement in their power conversion efficiencies. To achieve this goal, we perform a combinatorial materials study of metal oxide based light absorbers, charge transporters, junctions between them, and PV devices. Here we report the development of a combinatorial internal quantum efficiency (IQE) method. IQE measures the efficiency associated with the charge separation and collection processes, and thus is a proxy for PV activity of materials once placed into devices, discarding optical properties that cause uncontrolled light harvesting. The IQE is supported by high-throughput techniques for bandgap fitting, composition analysis, and thickness mapping, which are also crucial parameters for the combinatorial investigation cycle of photovoltaics. As a model system we use a library of 169 solar cells with a varying thickness of sprayed titanium dioxide (TiO2) as the window layer, and covarying thickness and composition of binary compounds of copper oxides (Cu-O) as the light absorber, fabricated by Pulsed Laser Deposition (PLD). The analysis on the combinatorial devices shows the correlation between compositions and bandgap, and their effect on PV activity within several device configurations. The analysis suggests that the presence of Cu4O3 plays a significant role in the PV activity of binary Cu-O compounds.
authors.affiliation: Department of Chemistry, Center for Nanotechnology & Advanced Materials, Bar Ilan University , 52900 Ramat Gan, Israel.
authors.forename: Assaf Y
authors.initials: AY
authors.lastname: Anderson
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Bouhadana
authors.forename: Hannah-Noa
authors.initials: HN
authors.lastname: Barad
authors.forename: Benjamin
authors.initials: B
authors.lastname: Kupfer
authors.forename: Eli
authors.initials: E
authors.lastname: Rosh-Hodesh
authors.forename: Hagit
authors.initials: H
authors.lastname: Aviv
authors.forename: Yaakov R
authors.initials: YR
authors.lastname: Tischler
authors.forename: Sven
authors.initials: S
authors.lastname: Rühle
authors.forename: Arie
authors.initials: A
authors.lastname: Zaban
mesh_terms: D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D003300:Copper / Q000737:chemistry*; D007834:Lasers; D010087:Oxides / Q000737:chemistry; D055668:Photochemical Processes; D011789:Quantum Theory
chemical_list: D010087:Oxides; D003300:Copper; C000520:cuprous oxide