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The effect of annealing on vertically aligned TiO_2 NWs deposited by glancing angle deposition(GLAD)method on Si substrate using pressed and sintered TiO_2 pellets as source material is studied.The FE-SEM images reveal the retention of vertically aligned NWs on Si substrate after annealing process.The EDS analysis of TiO_2NWs sample annealed at 600 ℃ in air for 1 h shows the higher weight percentage ratio of ~2.6(i.e.,72.27%oxygen and 27.73%titanium).The XRD pattern reveals that the polycrystalline nature of anatase TiO_2 dominates the annealed NWs sample.The electrical characteristics of Al/TiO_2-NWs/TiO_2-TF/p-Si(NW device) and Al/TiO_2-TF/p-Si(TF device) based on annealed samples are compared.It is riveting to observe a lower leakage current of ~1.32 × 10~(-7) A/cm~2 at +1 V with interface trap density of-6.71 × 10~(11)eV~(-1)cm~(-2)in NW device compared to ~2.23 × 10~(-2) A/cm~2 in TF device.The dominant leakage mechanism is investigated to be generally Schottky emission;however Poole-Frenkel emission also takes place during high reverse bias beyond 4 V for NWs and 3 V for TF device.
The effect of annealing on vertically aligned TiO_2 NWs deposited by glancing angle deposition (GLAD) method on Si substrate using pressed and sintered TiO_2 pellets as source material is studied. The FE-SEM images reveal the retention of vertically aligned NWs on Si substrate after annealing the EDS analysis of TiO_2NWs sample annealed at 600 ° C in air for 1 h shows the higher weight percentage ratio of ~ 2.6 (ie, 72.27% oxygen and 27.73% titanium). The XRD pattern reveals that the polycrystalline nature of anatase TiO_2 dominates the annealed NWs sample. The electrical characteristics of Al / TiO_2-NWs / TiO_2-TF / p-Si (NW device) and Al / TiO_2- TF / p-Si (TF device) based on annealed samples are compared. To observe a lower leakage current of ~ 1.32 × 10 -7 A / cm 2 at +1 V with interface trap density of-6.71 × 10-11 eV -1 cm -2 in NW device compared to ~ 2.23 × 10 ~ (-2) A / cm ~ 2 in TF device.The dominant leakage mechanism is investigated to be generally Schottky emission; howev Er Poole-Frenkel emission also takes place during high reverse bias beyond 4 V for NWs and 3 V for TF device.