Room-temperature optical properties of Al-doped ZnO nanowire array

Al-doped ZnO nanowire arrays were synthesized with An catalysis on Si( 100) substrate using the chemical vapor deposition technique. Only (002) diffraction peaks of ZnO can be found in the XRD patterns of the samples, which shows that the as-grown nanowires are highly crystalline in nature and grow along the [ 001] direction. The SEM images show that the ZnO nanowires are perpendicular to the substrate surface. Room-temperature photoluminescence ( PL) measurement shows 3 near band-edge emission peaks at 373, 375 and 389 nm. Analysis shows that the band gap of Al-doped ZnO nanowires is 3.343 eV and the exciton binding energy is 0.156 eV. Room-temperature PL spectrum of pure ZnO nanowaires shows 3 near band-edge emission peaks at 377, 379 and 389 nm. The band gap of pure ZnO nanowaires is 3.301 eV and the exciton binding energy is 0.113 eV, which shows that the band gap increases due to Al doping.