Presenter(s): Ashlee Vise − Chemistry
Faculty Mentor(s): James Young
Poster 49
Research Area: Natural/Physical Science
Funding: Department of Energy SULI Program
A photoelectrochemical cell (PEC) functions as an integrated water-splitting device using the sun’s energy to produce clean hydrogen gas. Barriers in the PEC field includes finding a cathode that has a (1) valence and conduction band that straddles the redox potentials of H2 and O2 , (2) photocurrent density greater than 1 mA/cm2, and (3) high photocurrent onset potential. Theoretical calculations have shown that different compositions of GaSbxP1-x alloys may meet these criteria. For this reason, we grew samples and performed a variety of characterization techniques to analyze the films. The present work shows that films with less than 13% antimony have IPCE (incident photon-to-current efficiency) of up to 60%, direct and indirect p-type band gaps that lie between ~2.0 and 2.2 eV, and photocurrent densities that reach 2 mA/cm2. These films show promising characteristics although they do not meet all of the requirements to perform unassisted water-splitting. Future work for this study includes growing more films that span a wider composition range in order to fully characterize the GaSbxP1-x material system.