Departmental Seminar

Electrically Injected Semiconductor Nanowire Lasers

Ms Nikita Gagrani
Australian National University

Nanowires are anisotropic 1D structures with diameters of several 10-100’s of nm while their lengths could be several microns long. This unique geometry leads to high aspect ratio, large surface to volume ratio and carrier/photon confinement in two dimensions which have several advantages. 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.

In this talk, I will first discuss the simulation results of InP single nanowire laser. I optimized dimensions of nanowire, doping concentration etc. to achieve low threshold lasing. Then, I will present the experimental methods to grow and fabricate single nanowire lasers. Strong electroluminescence from single nanowire has been achieved but some challenges still remain to achieve lasing. Issues related to the fabrication processes and factors such as losses to absorption from the metal contacts, non-uniform carrier injection, poor Ohmic contact, etc will be discussed. Finally, I will present some possible solutions to address these issues such as incorporation of quantum wells, using transparent conducting oxides for both carrier injection and doped layer etc.

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