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
conversion 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.