Plasmonic Light Scattering via Au Nanoparticles for Extended Photo Absorption in InGaN/GaN Multiquantum Wells for Unbiased Stable Solar-Driven Water Splitting

Herein, we investigated the influence of changing the number of InGaN/GaN quantum well pairs, optical bandgap tuning, and plasmonic coupling of Au nanoparticles (NPs) with multiquantum wells (MQWs) in photoelectrochemical (PEC) water splitting. MQWs displayed a 2-fold improvement in photocurrent density and applied bias photon-to-current con -version efficiency (ABPE%) as compared to reference GaN at zero bias. Tuning the optical band gap by varying the growth temperature of MQWs has also been shown to influence the performance of PEC water splitting. In comparison to the blue emission, the green emission sample showed a 15% improvement in photocurrent density and ABPE%. Decoration of MQWs with Au NPs significantly enhanced photocurrent density and stability. This is the first time that such a gigantic improvement in stability has been obtained for MQWs in PEC water splitting. Au NP/ MQWs showed 80% photocurrent retention after 13.9 h.