Improved solar hydrogen production by engineered doping of InGaN/GaN axial heterojunctions
Ng, Tien Khee
Ooi, Boon S.
KAUST DepartmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Electrical Engineering Program
Online Publication Date2019-01-28
Print Publication Date2019-02-18
Permanent link to this recordhttp://hdl.handle.net/10754/630957
MetadataShow full item record
AbstractInGaN-based nanowires (NWs) have been investigated as efficient photoelectrochemical (PEC) water splitting devices. In this work, the InGaN/GaN NWs were grown by molecular beam epitaxy (MBE) having InGaN segments on top of GaN seeds. Three axial heterojunction structures were constructed with different doping types and levels, namely n-InGaN/n-GaN NWs, undoped (u)-InGaN/p-GaN NWs, and p-InGaN/p-GaN NWs. With the carrier concentrations estimated by Mott–Schottky measurements, a PC1D simulation further confirmed the band structures of the three heterojunctions. The u-InGaN/p-GaN and p-InGaN/p-GaN NWs exhibited optimized stability in pH 0 electrolytes for over 10 h with a photocurrent density of about –4.0 and –9.4 mA/cm2, respectively. However, the hydrogen and oxygen evolution rates of the Pt-treated u-InGaN/p-GaN NWs exhibited a less favorable stoichiometric ratio. On the other hand, the Pt-decorated p-InGaN/p-GaN NWs showed the best PEC performance, generating approximately 1000 µmol/cm2 hydrogen and 550 µmol/cm2 oxygen in 10 h. The band-engineered p-InGaN/p-GaN axial NWs-heterojunction demonstrated a great potential for highly efficient and durable photocathodes.
CitationZhang, H., Ebaid, M., Tan, J., Liu, G., Min, J.-W., Ng, T. K., & Ooi, B. S. (2019). Improved solar hydrogen production by engineered doping of InGaN/GaN axial heterojunctions. Optics Express, 27(4), A81. doi:10.1364/oe.27.000a81
PublisherThe Optical Society