InP nanowire p-type doping via Zinc indiffusion

• Novel pathway for p-type doping for InP nanowires.
• Post-diffusion annealing beneficial with ZnP caps.
• Achieved carrier concentrations up to 1018 cm−3
• Effects of interstitial and substitutional Zn on electrical behavior.
• Effects of interstitial and substitutional Zn on photoluminescence.

We report an alternative pathway for p-type InP nanowire (NW) doping by diffusion of Zn species from the gas phase. The diffusion of Zn was performed in a MOVPE reactor at 350–500 °C for 5–20 min with either H2 environment or additional phosphorus in the atmosphere. In addition, Zn3P2 shells were studied as protective caps during post-diffusion annealing. This post-diffusion annealing was performed to outdiffuse and activate Zn in interstitial locations. The characterization methods included photoluminescence and single NW conductivity and carrier concentration measurements. The acquired carrier concentrations were in the order of >1017 cm−3 for NWs without post-annealing, and up to 1018 cm−3 for NWs annealed with the Zn3P2 shells. The diffused Zn caused redshift to the photoluminescence signal, and the degree of redshift depended on the diffusion process.