Light harvesting is central to many photonic materials. The light harvesting efficiency in these materials is, however, generally reduced because upper excited‐state energy is lost by energy‐dissipating internal conversion (IC) and vibrational relaxation processes. Herein, size‐dependent energy harvesting from nonthermalized, upper excited states of glutathione‐protected gold clusters of various sizes, including Au18, Au22, Au25, Au67, Au102, and Au≈940, is reported. Femtosecond transient absorption measurements reveal that the IC processes of Au18, Au22, and Au25 are relatively slow wherein the upper excited‐state energy of gold clusters efficiently is harvested by an energy acceptor, aminofluorescein (AF), covalently attached to the gold cluster on the time scales of 150 fs (Au18), 220 fs (Au22), and 380 fs (Au25). Steady‐state photoluminescence measurements of AF‐conjugated Au18, Au22, and Au25 clusters show notable AF emission upon high‐energy excitation of gold clusters. Herein, a new avenue for energy harvesting from nonthermalized upper excited states of gold clusters, which would otherwise be lost as heat, is opened up.

Organic electronic materials have advantages over inorganics in terms of versatility, cost, and processability. Recent advancements in organic materials for light-emitting diodes (OLED), field effect transistors (OFET), and photovoltaics have engendered extensive innovation potential on this field. In this research, we focus on synthesizing SQ (silsesquioxane) based oligomers cross-linked by dibromo-aromatic linkers and explore how the cross-linker influences their photophysical properties. Bis-trialkoxy silyl (linker) model compounds were synthesized to compare noncage photophysical properties with the oligomers. Several techniques such as UV/vis, fluorescence, FTIR, and thermal gravimetric analysis (TGA) have been used to characterize the systems. Time-resolved fluorescence and femtosecond transient absorption spectroscopy were used to understand the excited state dynamics of these materials. Studies were carried out to understand the differences between monomers and oligomers and potential energy transfer and charge transfer between the cages and cross-linking chromophores. Transient absorption showed lower energy absorption from the excited states, suggesting short-range communication between moieties. Single photon counting studies have shown distinct lifetime differences between most linkers and cages display possible excitation energy transfer through these materials. Transient absorption anisotropy measurements have shown signatures for excitation energy transfer between linker chromophores for oligomeric compounds. The silsesquioxane (SQ) backbone of the oligomers gives substantial thermal stability as well as solution processability, giving better flexibility for achieving energy transfer between linking chromophores.