While semiconductor electrochemiluminescence can be characterized by emitter luminance or electrode photovoltage, its practical performance is determined by a much more stringent interfacial consideration – whether the same interface can maintain chemical integrity, electronic openness, optical accessibility, and analytical function while generating radicals in water. This investigation examines transparent conducting oxides, covered and uncovered silicon, porous silicon, oxide photoanodes, hot-electron silicon and aluminium electrodes, Cd-containing and low-toxicity quantum dots, tin sulfide quantum dots, sulfur quantum dots, and lead-halide perovskite nanocrystals. All material systems are evaluated according to five interfacial criteria: low potential or photovoltage gain, stability against corrosion or passivation, charge transfer availability, optical or spatial addressability, and assay capability. It is found that the most functional aqueous interface is not the bare semiconductor with maximal theoretical band advantage, but that which finds the optimal compromise between chemical protection and carrier availability. Metal-insulator-semiconductor silicon photoanodes yield the best combination of photovoltage gain, backside illumination, and designed passivation, while uncovered silicon cannot satisfy the same criterion due to oxide blocking; oxide photoanodes like TiO$_2$, WO$_3$, BiVO$_4$, and $\alpha$-Fe$_2$O$_3$ exhibit good intrinsic chemical stability but are limited by light absorption, charge transport, and interfacial kinetics. Quantum dots afford the greatest flexibility of spectroscopic and multiplexed assays, including detection at picogram-per-millilitre and femtomolar concentrations of antibodies and nucleic acids in established assays, but their chemical stability is determined by defect density of shells, ligands, traps, and ion movement, not corrosion of macroscale electrodes. Design lesson is that semiconductor ECL needs to involve corrosion-limited charge transfer.

semiconductor electrochemiluminescence,photoinduced electrochemiluminescence,silicon passivation,corrosion-gated charge transfer,quantum dots,semiconductor/liquid junction,spatial electrochemiluminescence