Wireless Anti-Stokes Photoinduced Electrochemiluminescence at Closed Semiconducting Bipolar Electrodes

Abstract

Wireless electrochemical systems constitute a rapidly developing field. Herein, photo-induced electrochemiluminescence (PECL) is studied at Si-based closed bipolar electrodes (BPEs) for designing anti-Stokes systems that can convert IR into visible photons, without direct electrical contact. We show that protection of the anodic emitting pole of the BPE allows the triggering of bright and longstanding emission under the synergetic actions of an external bias and IR illumination. Photoactive nand p-type Si BPEs are studied with front-side and back-side illumination, respectively, and non-photoactive n + -Si BPEs are studied in the dark. Two electrochemiluminescent (ECL) systems ([Ru(bpy) 3 ] 2+ /TPrA and L-012) are tested and we show that the onset bias and the anti-Stokes shift can be controlled by the ECL system that is employed. These advances, rationalized by simulations, will be useful for the design of original PECL systems for chemical sensing or photodetection.

Square-Wave Voltammetry Enables Measurement of Light-Activated Oxidations and Reductions on n-Type Semiconductor/Metal Junction Light-Addressable Electrochemical Sensors

“…Gooding and co-workers showed that Au NPs attached to n-Si using a self-assembled monolayer were able to measure redox species over a fairly broad potential range (−0.25 to 0.25 V) . Sojic, Loget, and co-workers employed MIS junctions to perform photoinduced electrogenerated chemiluminescence (ECL), which enables ECL at very low applied potentials and may lead to exciting new imaging strategies for biological samples. − …”

Square wave voltammetry enables measurement of light-activated oxidations and reductions on n-type semiconductor/metal junction light-addressable electrochemical sensors

“…47 Sojic, Loget, and coworkers employed MIS junctions to perform photoinduced electrogenerated chemiluminescence (ECL), which enables ECL at very low applied potentials and may lead to exciting new imaging strategies for biological samples. [48][49][50][51][52][53] One major challenge for LAES using semiconductor/metal (as well as semiconductor/liquid) junctions is that only one electrochemical reaction (either oxidation or reduction) will be activated by light.…”

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

“…This shift of onset potential (here E0.5 V) is characteristic of a conventional photoanode behavior and caused by the generation of a photovoltage, this was already observed (to a lower extent) on non-patterned n-Si/SiO x /Ir photoanodes. 63,73 We then studied the evolution of PECL on the illuminated n-Si/SiO x /Ir over time by potentiostatic measurement at 0.8 V for 30 min while capturing microscopy pictures. The PECL intensity averages were measured on the pictures for the 50 mm/ 100 mm, 25 mm/50 mm, 10 mm/50 mm, and 5 mm/50 mm microbands.…”

“…This shift of onset potential (here ≈0.5 V) is characteristic of a conventional photoanode behavior and caused by the generation of a photovoltage, this was already observed (to a lower extent) on non-patterned n-Si/SiO x /Ir photoanodes. 63,73…”