Optical and electrical properties of ZnO films were investigated by the photoluminescence (PL) and hall measurements. Thin films of ZnO were deposited by atomic layer deposition (ALD) with the different feed times of DEZn and H2O precursor. As the feed times of DEZn and H2O precursors increased, the intrinsic carrier concentration of ZnO film decreased from 6.29 × 1019 to 4.13 × 1019/cm3. Room temperature PL spectra of ZnO films represented two emission bands which consisted of the near bandedge (~ 380 nm) and the deep level emissions (~ 510 nm). The deep level emission was thought be ascribed to the native defects such as Zn vacancy (VZn) and oxygen vacancy (VO), etc. With increasing the feed time of diethylzinc (DEZn, Zn(C2H5)2) and H2O, PL intensity of near bandedge emission was increased, while that of deep level emission was decreased. These results respects that the native defects such as VZn and VO were significantly reduced by the feed time of DEZn and H2O, resulting in the low intrinsic carrier concentration as well as the elimination of deep level transition.
Keywords: ZnO, ALD, PL, HR-XRD, Hall