Silver photodiffusion into amorphous Ge chalcogenides

Silver photodiffusion into amorphous chalcogenides involves the movement of ions controlled by a UV-visible light illumination, and has potential application to memory devices. Understanding the kinetics of this phenomenon will expand the range of possible applications. Herein, we report the excitation photon energy dependence of the silver photodiffusion kinetics in Ag/amorphous Ge20S80/Si substrate stacks, probed by neutron reflectivity using four light-emitting diodes with different peak wavelengths. Time-dependent changes were clearly observed in all three of the Ag/Ag-doped reaction/chalcogenide host layers, in terms of layer thickness, scattering length density, and roughness. Silver photodiffusion effectively occurred when the excitation photon energy was greater than the optical gap of the chalcogenide host material. Excitation of lone-pair electrons to anti-bonding states at the chalcogenide layer therefore appears to play a crucial role in triggering silver photodiffusion.

Hot electron transfer in Zn–Ag–In–Te nanocrystal–methyl viologen complexes enhanced with higher-energy photon excitation

Zn–Ag–In–Te nanocrystals exhibited hot electron transfer to adsorbed methyl viologen, the efficiency being enhanced from 45% to 72% with an increase in the excitation photon energy.

Generation and Transport of Photocarriers in Head-Tail Poly(3-Alkylthiophene) Films

ABSTRACTPhotovoltaic effects in Schottky Junction cells composed with Au/head-tail poly(3-hexylthiophene) (HT-P3HT)/Al have been studied as a function of excitation photon energy and temperature. It has been found that photocarriers are effectively generated at the interface of HT-P3HT/Al from the excitation spectra of photocurrents (photoaction spectra), which were obtained upon illumination to the Au or Al sides. The photoaction spectra also suggest that the photocarrier generation occurs at around 2.3 eV and 3.5 eV, which correspond to the peak of φ-φ* absorption and the photon energy with lower optical density region, respectively. The mechanisms of photocarrier generation are discussed taking the role of the Schottky junction into consideration.