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Published March 10, 2014 | public
Journal Article

Mapping Quantum Yield for (Fe−Zn−Sn−Ti)O_x Photoabsorbers Using a High Throughput Photoelectrochemical Screening System

Abstract

Combinatorial synthesis and screening of light absorbers are critical to material discoveries for photovoltaic and photoelectrochemical applications. One of the most effective ways to evaluate the energy-conversion properties of a semiconducting light absorber is to form an asymmetric junction and investigate the photogeneration, transport and recombination processes at the semiconductor interface. This standard photoelectrochemical measurement is readily made on a semiconductor sample with a back-side metallic contact (working electrode) and front-side solution contact. In a typical combinatorial material library, each sample shares a common back contact, requiring novel instrumentation to provide spatially resolved and thus sample-resolved measurements. We developed a multiplexing counter electrode with a thin layer assembly, in which a rectifying semiconductor/liquid junction was formed and the short-circuit photocurrent was measured under chopped illumination for each sample in a material library. The multiplexing counter electrode assembly demonstrated a photocurrent sensitivity of sub-10 μA cm^(–2) with an external quantum yield sensitivity of 0.5% for each semiconductor sample under a monochromatic ultraviolet illumination source. The combination of cell architecture and multiplexing allows high-throughput modes of operation, including both fast-serial and parallel measurements. To demonstrate the performance of the instrument, the external quantum yields of 1819 different compositions from a pseudoquaternary metal oxide library, (Fe–Zn–Sn–Ti)O_x, at 385 nm were collected in scanning serial mode with a throughput of as fast as 1 s per sample. Preliminary screening results identified a promising ternary composition region centered at Fe_(0.894)Sn_(0.103)Ti_(0.0034)O_x, with an external quantum yield of 6.7% at 385 nm.

Additional Information

© 2014 American Chemical Society. Received: June 21, 2013. Revised: October 8, 2013. Publication Date (Web): January 28, 2014. This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award Number DE-SC000499. We gratefully acknowledge critical support and infrastructure provided for this work by the Kavli Nanoscience Institute at Caltech.

Additional details

Created:
August 19, 2023
Modified:
October 25, 2023