Microstructural and Photoluminescence Property Changes in Ion‐implanted GaAs/GaAs:Si/Al x Ga 1−x As Core–shell Nanowires

Nanostructured semiconductors have unique physical properties that can have many applications, including optoelectronics, nanoelectronics, etc. Functionalization of nanoelectronic devices often requires specific electrical properties in different regions of the nanowire to form a p‐n junction or ohmic contact. Such locally doped regions can be created by selective ion implantation. In the present work, we investigated the microstructure and optical properties of GaAs/GaAs:Si/Al x Ga 1−x As core–shell nanowires after ion implantation and postimplantation annealing. GaAs/GaAs:Si/Al x Ga 1−x As core–shell nanowires were implanted with sulfur ions at a fluence of 2.3 × 10 15 cm −2 . After ion implantation, the nanowires were subjected to flash‐lamp annealing (FLA) for 3.2 ms or to conventional rapid thermal annealing (RTA) for 90 s. Raman and microstructural analyses indicate that FLA treatment with an energy density of 102 J cm −2 can almost fully restore the original crystalline quality of the nanowires. On the other hand, photoluminescence (PL) measurements show that nanowires subjected to RTA exhibit a stronger emission intensity; however, RTA at 550°C leads to severe decomposition of the Al x Ga 1−x As shell.