Open AccessThe effect of laser irradiation on ZnO thin films
Author(s) -
Zhao Yan,
Yijian Jiang
Publication year - 2010
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.59.2679
Subject(s) - materials science , irradiation , laser , exciton , optoelectronics , excimer laser , emission intensity , surface roughness , optics , photoluminescence , condensed matter physics , composite material , physics , nuclear physics
The effect of KrF pulsed excimer laser irradiation on intrinsic defectsultra-violet (UV) emission and surface morphology of ZnO thin films was investigatedand also the origin of room temperature UV emission was discussed in detail. It was found thatthe KrF laser can break the Zn—O bonds; thereforethe concentration of VO (or Zni) defects increasesleading to the decrease of resistivity and increase of carrier concentration. By adjusting the laser energy densitiesthe donor defect concentration can be controlled in a wide range. Simultaneouslyunder the heat of laserthe melting grains connect with each otherresulting in the great decrease of surface roughness. Room temperature UV emission of ZnO film is composed of contribution from free-exciton (FX) recombination and its longitudinal-optical phonon replica (FX-LO), the defect density determines the relative strengths of FX to FX-LO emission intensitieswhich strongly affect the peak position and intensity of UV emission of ZnO film. This investigation indicates that the laser irradiation is an effective technique to modulate the exciton emission by controlling the defect densitywhich is important for the application of high performance of UV emitting optoelectronic devices.