O2 photodesorption from AuO 2 − and Au2O 2 −

Abstract

Using time-resolved photoelectron spectroscopy, the decay channels of AuO − 2 and Au 2 O − 2 following photoexcitation with 3.1-eV photons have been studied. For AuO − 2 , a state with a rather long lifetime of 30 ps has been identified. Its decay path could not be determined but photodesorption can be excluded. For Au 2 O − 2 , the spectra indicate O 2 desorption after 3.1-eV photoexcitation on a time scale of 1 ps. While comparing these results on Au n O − 2 with analogous data on Ag n O − 2 clusters, a discernible pattern emerges: for dissociatively bound O 2 (AuO − 2 , Ag 3 O − 2), there are longliving excited states which do not decay by oxygen desorption, while for molecular chemisorption (Au 2 O − 2 , Ag 2 O − 2 , Ag 4 O − 2 , Ag 8 O − 2), the 3.1-eV photoexcitation triggers fast O 2 desorption with a high quantum yield.

Energy‐Band Engineering by Remote Doping of Self‐Assembled Monolayers Leads to High‐Performance IGZO/p‐Si Heterostructure Photodetectors

“…To implement highperformance photodetectors that meet the performance requirements of the abovementioned applications, research efforts are accelerating on the utilization of emerging semiconductor materials (such as metal oxides, [5] transition metal dichalcogenides, [6] perovskites, [7] and other organic materials [8] ) accompanied by nanotechnology.Metal oxide semiconductors (MOSs) is a potential candidate for resolving the existing needs from advanced photodetectors: large-area synthesis, a low-temperature process, and compatibility with conventional fabrication equipment. Owing to the abovementioned attributes of the MOS, photoconductive-, photogating-, photodiode-, or phototransistor-type detectors using various combinations of metal oxides (including ZnO, [9] AuO, [10] SnO 2 , [11] CuO, [12] and ZnSnO, [13] and indium-gallium-zinc oxide (IGZO) [14] ) are being developed extensively. However, with these materials, there are still limitations: 1) the oxide surface of the MOS suffers from charge traps and operational instability, degrading photodetection performance; [5] and 2) the absence of an appropriate doping technique for the MOS is an obstacle for process developments that improve photodetection performance.…”