Compound semiconductor nanowires are promising solution for nanoscale lasers owing to their unique geometry which acts as a cavity/natural optical resonator and high gain provided by the material. These nanoscale lasers can be used in a wide range of applications such as on-chip optical routing, coherent light sources for meta-optics, photonics integrated circuits and as probes for the single cells. While most of the studies on nanowire lasers are focused on optically pumped lasing, electrical injection is required for practical applications which is still elusive.
In this talk, I will first discuss the simulation results of both axial and radial InP single nanowire laser. The length and diameter of the nanowire together with the doping concentration are optimised to achieve low threshold lasing. Experimental methods to grow these nanowires and fabrication of these devices will then be briefly outlined. Strong electroluminescence from both axial and radial nanowires are achieved. The performance of axial vs radial InP nanowires will be compared and discussed, in particular to some challenges related to achieving lasing such as optical losses due to absorption from the metal contacts and dopants, poor Ohmic contact, . To address these issues, different transparent conducting oxides are investigated as both the carrier injection and contact layer. These transparent conducting oxide layers are then deposited on the nanowires to form radial heterojunction devices such as p-InP/n-ZnO, p-InP/n-SnOx and n-InP/p-SnNiOx. All devices exhibit excellent light emitting diodes properties. The effect of temperature on the light emitting properties of these devices will then be presented and discussed. Finally, I will discuss some issues that are impeding lasing in these devices such as non-uniform current injection, heat dissipation issues and asymmetry in carrier injection.
Meeting ID: 893 8081 5031