Localized Visible Wavelength Photoluminescence from GaP/InP Heterostructure Nanowires

We demonstrate growth of gallium phosphide (GaP) segments within indium phosphide (InP) nanowires (NWs), which forms GaP/InP heterostructure NWs. The GaP segments emit visible wavelength photoluminescence (PL) at 540 and 620 nm with and without growth interruption during growth, respectively, while the emission decay times are 8.0 and 6.0 ns, respectively, and the InP NWs emits PL at 870 nm. The visible wavelength emission of GaP is shown from PL mapping to be localized from the GaP segments. Furthermore, the PL emission is shown to be polarization-dependent. Both InP NWs and GaP segments tend to have polarizations in parallel directions of NWs as expected from their zinc blende structures. The experimentally obtained band gap values are verified with band structure calculations using density functional theory. We observed that the band gap of InP NWs of 1.41 (in experiment) to 1.65 eV (in simulation) slightly increases by 0.01???0.02 eV upon GaP segment incorporation. Such a study will help us to tune the emission and optical properties of GaP/InP NWs for future light sources in the information and communication technology applications. Superscript/Subscript Available

Automated summary

We successfully demonstrate the growth of gallium phosphide (GaP) segments within indium phosphide (InP) nanowires, forming GaP/InP heterostructure nanowires. The GaP segments show visible wavelength photoluminescence (PL) during growth, while the InP nanowires emit infrared light. PL mapping and polarization analysis reveal that the emission mainly comes from the GaP segments. The experimentally obtained band gap values are verified with band structure calculations. This study contributes to the tuning of emission and optical properties of GaP/InP nanowires for future applications in information and communication technology.