The family of copper antimony selenides
is important for renewable
energy applications. Several phases are accessible within narrow energy
and compositional ranges, and tunability between phases is not well-established.
Thus, this system provides a rich landscape to understand the phase
transformations that occur in hot-injection nanoparticle syntheses.
Rietveld refinements on X-ray diffraction patterns model anisotropic
morphologies to obtain phase percentages. Reactions targeting the
stoichiometry of CuSbSe2 formed Cu3SbSe3 before decomposing to thermodynamically stable CuSbSe2 over time. An amide base was added to balance cation reactivity
and directly form CuSbSe2. Interestingly, Cu3SbSe3 remained present but converted to CuSbSe2 more rapidly. We propose that initial Cu3SbSe3 formation may be due to the selenium species not being reactive
enough to balance the high reactivity of the copper complex. The unexpected
effect of a base on cation reactivity in this system provides insight
into the advantages and limitations for its use in other multivalent
systems.