Fabrication of InGaN/Si (111) nanowire heterostructure photoanode for hydrogen generation under visible light

Abstract

Group III-nitride alloys are believed to be promising photoelectrodes for photoelectrochemical water splitting to get hydrogen fuel. Here, we grew the InGaN nanowires (NWs) on silicon (111) as a photoanode using a low-cost chemical vapor deposition method. The photocurrent of an InGaN NWs' photoanode is five times greater than that of a GaN NWs' photoanode. The maximum photocurrent density of 8 mA/cm2 at 0.5 V vs the reverse hydrogen electrode with an applied bias photon-to-current efficiency of 5.8% was observed in the In30Ga70N NWs/Si (111) heterostructure. The incident photon-to-current conversion efficiency of 19.1% at 520 nm was observed for In30Ga70N NWs' photoanodes, which is much higher than GaN NWs. The hydrogen generation rates are 42.3 μmol/cm2 h at 0.15 V under 100 mW/cm2 white light irradiation. This InGaN/Si heterostructure photoanode improves photoelectrochemical performance for hydrogen fuel generation, paving the path for future development at a lower cost and on a larger scale.

Use of Gold Nanoparticles in Indium Gallium Nitride Growth for Improving the Photoactive Electrical Performance of p–n Junctions

“…51 The band and shoulder observed at 2.62 and 2.26 eV, respectively, are commonly attributed to luminescence produced by native defect states in the material. 52,53 The InGaN films grown on AuNPs show a small band close to the energy of the NBE, as observed in Figure 7b. In addition, the defect emission is present with a higher intensity than the previous one.…”

“…Additionally, a higher-intensity emission between 3.1 and 2.8 eV can be observed and attributed to InGaN NBE because of the shift toward a lower energy according to the indium composition . The band and shoulder observed at 2.62 and 2.26 eV, respectively, are commonly attributed to luminescence produced by native defect states in the material. , …”