Local reactivity of metal–insulator–semiconductor photoanodes imaged by photoinduced electrochemiluminescence microscopy

Abstract

Localized photoinduced electrochemiluminescence (PECL) is studied on photoanodes composed of Ir microbands deposited on n-Si/SiOx. We demonstrate that PECL microscopy precisely imaged the hole-driven heterogeneous photoelectrochemical reactivity. The method is...

Near-IR Photoinduced Electrochemiluminescence Imaging with Structured Silicon Photoanodes

“…To promote charge transfer at the solid/liquid interface and avoid electrical passivation that generally occurs on bare Si anodes and leads to their rapid deactivation, − an Ir thin film (nominal thickness = 2 nm) was deposited onto the Si MP array by magnetron sputtering (as detailed in Section ). This was performed to create a n -Si/SiO x /Ir MIS junction, which has been proven particularly efficient for promoting photogenerated charge transfer at Si photoanodes, in the field of water splitting − and PECL. ,, Backscattered SEM images (Figure S2) of a single pillar revealed that the sputtering process produced a conformal Ir thin film on the top of the pillars and a gradient of isolated Ir nanoparticles (NPs) on the pillars’ sidewalls (Figure c), as well as on the inner space (Figure S2d). XPS (Figure d) confirmed the SEM observation by exhibiting intense Ir 4f, 4d, and O 1s peaks (attributed to Si and Ir surface oxides), less intense Si 2p, 2s peaks, and weak C 1s and N 1s peaks (attributed to adventitious contaminants) …”

Infrared photoinduced electrochemiluminescence microscopy of single cells

“…49 PECL has been used to photoaddress charge transfer at a local level and therefore to partially activate the electrode, either with the incident light or with the use of a heterogeneous electrode. 47,51 Recently, Xu and co-workers imaged the activity of single gold nanoparticles on a TiO 2 surface using PECL, 52 and our group investigated the local reactivity of Ir microbands on Si/SiO x using PECL microscopy. 51 To the best of our knowledge, PECL microscopy has not been reported so far for biological samples.…”

“…47,51 Recently, Xu and co-workers imaged the activity of single gold nanoparticles on a TiO 2 surface using PECL, 52 and our group investigated the local reactivity of Ir microbands on Si/SiO x using PECL microscopy. 51 To the best of our knowledge, PECL microscopy has not been reported so far for biological samples.…”