Increased spatial randomness and disorder of nucleates in dark-phase electrodeposition lead to increased spatial order and pattern fidelity in phototropically grown Se-Te electrodeposits.

The role of nucleation was investigated during phototropic growth of Se-Te. Under low levels of mass deposition (mass equivalent of -3.75 mC cm-2 of charge passed) that produced small nucleate spacings, patterns in photoelectrochemically deposited Se-Te films converged at relatively earlier levels of mass deposition and ultimately exhibited higher pattern fidelity throughout pattern development as compared to pattern formation from larger initial nucleate spacings. Consistently, use of an applied striking potential during very early levels of mass deposition produced more spatially random dark-phase electrodeposited nucleates and led to phototropic Se-Te photoelectrodeposited films that exhibited improved pattern fidelity relative to depositions performed with no striking step. Collectively, the data indicate that increases in randomness and spatial disorder of the dispersion of the initial nucleates produces increases in the fidelity and spatial order in the resulting phototropically grown electrodeposits.