High-Throughput Characterization of Structural and Photoelectrochemical Properties of a Bi-Mo-W-O Thin-Film Materials Library

A Bi-W-Mo-O thin-film materials library was fabricated by combinatorial reactive magnetron sputtering. The composition spread was investigated using high-throughput methods to determine crystalline phases, composition, morphology, optical properties, and photoelectrochemical performance. The aurivillius phase (Bi2O2)(2+) (Bi-M(W1-NMoN)(M-1)O3M+1)(2-) is the predominantly observed crystal structure, indicating that the thin films in the library are solid solutions. With increasing amounts of Mo (sic) 7-22% the diffraction peak at 2 theta = 28 degrees (sic) [131] shifts due to lattice distortion, the photoelectrochemical activity is increasing up to a wavelength of 460 nm with an incident photon to current efficiency (IPCE) of 4.5%, and the bandgap decreases. A maximum photocurrent density of 31 mu A/cm(2) was measured for Bi31W62Mo7Oz at a bias potential of 1.23 V vs. RHE (0.1 M Na2SO4).