Strain-Induced Confinement of Excitons in Quasi-free AgI Nanoparticles

Abstract

The optical spectra of vapor quenched metastable Ag−Cu thin films progressively iodized under ambient conditions have been measured. Delayed evolution and inhomogeneous broadening of the exciton absorption at 420 nm of the spatially confined γ-AgI nanoparticles were clearly seen by the development of Z 1,2 exciton peak − iodization being controlled by the as-quenched Ag−Cu clusters. Cu addition not only restricts the particle size, but also favors the island type growth mode.

Plasmon-exciton transition in Cu thin films on iodization

“…The SPR of copper is seen to be very weak compared to that in silver [3] The iodized films give two exciton transitions at about 410 nm (Z 1,2 ) and 330 nm(Z 3 ) [5]The Energy Band gap is found to be 3.03 eV which is comparable to the standard value of 2.9 eV. The blue shift of 0.13 eV could perhaps be due to confinement effects usually seen in nanostructures [4] The subtle plasmon-exciton transition in Cu occurs over 2 hours' iodization.…”

“…ones. Earlier Cu-substituted Ag films have shown retarded iodization kinetics besides a decreased crystallite size [4]. The stronger Cu-I bond (than Ag-I bond) and reactivity of Cu towards ambient oxygen could be the causes.…”

Nanophases in mechanochemically synthesized AgI–CuI system: structure, phase stability and phase transitions

“…Structure of b-and g-AgI and CuI, Vegard's law and particle size of g-AgI besides assisting in particle size reduction. g-AgI nanoparticles were clearly seen upon progressively iodized Ag -Cu metastable alloy thin films under ambient conditions, which have been studied, by optical absorption and photoluminescence [11]. The Ag 0.95 Cu 0.05 I ðx ¼ 0:05Þ sample (pattern (b)) has two b-AgI lines (100) show predominant peaks corresponding to the zincblende structure of g-AgI alone.…”

Synthesis and optical properties of hybrid “plasmon-exciton” nanostructures based on Ag-AgI in nanoporous silica glass

“…As a rule, AgI is synthesized and studied in the form of granular thin films [16][17][18][19]. In such films, neigh boring grains interfere with each other.…”