Solar Hydrogen Production Using III-Nitride Nanowire Photoelectrode

The energy generation either via solar cells (SC) or photoelectrochemical (PEC) cells is becoming more and more important for catering the energy demands of the world. The PEC process conversion provides hydrogen (H2), methanol (CH3OH), or some other alkanes molecules as output fuels that can store a remarkable amount of energy/unit mass. Semiconductors especially Group-III nitrides (especially InGaN alloys) can offer several advantages to the design of photoelectrodes for PEC cells used for water splitting, such as it is possible to tune its bandgap from 0.65 to 3.40 eV, thus they have the potential for entire solar spectrum applications. The photocatalytic activity seems to be further improved by using nanostructures of InGaN/GaN, due to the improvement in optical absorption through light trapping, improved surface to volume ratios and swift charge carrier separation. However, to improve the PEC conversion efficiency from III-nitride materials based structures, it is required that these semiconductor layer surfaces have to be stabilized and should be engineered with catalysts, that can be either molecular or inorganic, to modify the kinetics of desired reactions pathways. During the course of the chapter, we will discuss the current state of the art in the field and strategies for designing and developing an efficient PEC solar fuel cell using III-nitride photoelectrode assisted by nanopatterning.