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 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.

Influence of Substrates on the Long-Range Order of Photoelectrodeposited Se-Te Nanostructures.

The long-range order of anisotropic phototropic Se-Te films grown electrochemically at room temperature under uniform-intensity, polarized, incoherent, near-IR illumination has been investigated using crystalline (111)-oriented Si substrates doped degenerately with either p- or n-type dopants. Fourier-transform (FT) analysis was performed on large-area images obtained with a scanning electron microscope, and peak shapes in the FT spectra were used to determine the pattern fidelity in the deposited Se-Te films. Under nominally identical illumination conditions, phototropic films grown on p-Si(111) exhibited a higher degree of anisotropy and a more well-defined pattern period than phototropic films grown on n-Si(111).

Direct Observation of a Charge-Transfer State Preceding High-Yield Singlet Fission in Terrylenediimide Thin Films.

Singlet exciton fission (SF) in organic chromophore assemblies results in the conversion of one singlet exciton (S) into two triplet excitons (T), provided that the overall process is exoergic, i.e., E(S) > 2E(T).