Effect of an Ultraviolet-Ozone Treatment on the Electrical Properties of Titanium-Oxide Thin-Film Transistors Fabricated by Using a Sol-Gel Process

Chong, Ho Yong; Lee, Se Han; Kim, Tae Whan

doi:10.1149/2.016207jes

Cited by 13 publications

(14 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The O 1s signals are known to be affected by oxygen treatment. ,, The O 1s signals contain three contributions (Table ). (i) A signal at 530.0 eV corresponds to oxygen that is bound to coordinatively saturated titanium atoms (red curve Figure ).…”

Section: Resultsmentioning

confidence: 99%

“…UV–ozone treatment was used to change the concentration of surface oxygen vacancies in TiO 2 . Several groups studied the influence of UV/UV–ozone treatments on TiO 2 and its effect on PSC efficiency. − Some possible explanations for this beneficial effect, such as an increased wettability originating from the UV–ozone treatment, were presented.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Removal of Surface Oxygen Vacancies Increases Conductance Through TiO₂ Thin Films for Perovskite Solar Cells

Klasen

Baumli

et al. 2019

J. Phys. Chem. C

View full text Add to dashboard Cite

We report that UV–ozone treatment of TiO2 anatase thin films is an efficient method to increase the conductance through the film by more than 2 orders of magnitude. The increase in conductance is quantified via conductive scanning force microscopy on freshly annealed and UV–ozone-treated TiO2 anatase thin films on fluorine-doped tin oxide substrates. The increased conductance of TiO2 anatase thin films results in a 2% increase of the average power conversion efficiency (PCE) of methylammonium lead iodide-based perovskite solar cells. PCE values up to 19.5% for mesoporous solar cells are realized. The additional UV–ozone treatment results in a reduced number of oxygen vacancies at the surface, inferred from X-ray photoelectron spectroscopy. These oxygen vacancies at the surface act as charge carrier traps and hinder charge extraction from the adjacent material. Terahertz measurements indicate only minor changes of the bulk conductance, which underlines the importance of UV–ozone treatment to control surface-based defects.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Removal of Surface Oxygen Vacancies Increases Conductance Through TiO₂ Thin Films for Perovskite Solar Cells

Klasen

Baumli

et al. 2019

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…The lower binding energy peaks near 530.6 eV are attributed to the lattice oxygen atoms of the In-O and Zn-O chemical bonds. However, the shoulders in the spectral region between 531.0 and 534.0 eV are attributed to oxygen deficiency and the hydroxide group, which originate from the oxygen vacancy ( V O ) and the surface-adsorbed hydroxyl oxygen atoms (M-OH) [ 26 ]. Figure 3 b shows the results from the deconvoluted XPS spectra of O 1s for the ZnO and In-doped ZnO thin films.…”

Section: Resultsmentioning

confidence: 99%

Low-Concentration Indium Doping in Solution-Processed Zinc Oxide Films for Thin-Film Transistors

et al. 2017

View full text Add to dashboard Cite

We investigated the influence of low-concentration indium (In) doping on the chemical and structural properties of solution-processed zinc oxide (ZnO) films and the electrical characteristics of bottom-gate/top-contact In-doped ZnO thin-film transistors (TFTs). The thermogravimetry and differential scanning calorimetry analysis results showed that thermal annealing at 400 °C for 40 min produces In-doped ZnO films. As the In content of ZnO films was increased from 1% to 9%, the metal-oxygen bonding increased from 5.56% to 71.33%, while the metal-hydroxyl bonding decreased from 72.03% to 9.63%. The X-ray diffraction peaks and field-emission scanning microscope images of the ZnO films with different In concentrations revealed a better crystalline quality and reduced grain size of the solution-processed ZnO thin films. The thickness of the In-doped ZnO films also increased when the In content was increased up to 5%; however, the thickness decreased on further increasing the In content. The field-effect mobility and on/off current ratio of In-doped ZnO TFTs were notably affected by any change in the In concentration. Considering the overall TFT performance, the optimal In doping concentration in the solution-processed ZnO semiconductor was determined to be 5% in this study. These results suggest that low-concentration In incorporation is crucial for modulating the morphological characteristics of solution-processed ZnO thin films and the TFT performance.

show abstract

“…The oxide TFT could be annealed at a higher temperature (>500 °C) to improve its performance and stability, but higher annealing temperature prevents the use of the plastic substrate for the flexible display . Also, various process technologies are developed to improve the film quality, for example, Ar/O 2 plasma treatment, O 2 annealing, and UV ozone treatment . Many of the previous reports have focused on the thin‐film quality and lowering fabrication process temperature by using the UV treatment or combustion method .…”

Section: Introductionmentioning

confidence: 99%

High Performance of a‐IZTO TFT by Purification of the Semiconductor Oxide Precursor

Bukke

Mude

Saha

et al. 2019

Adv Materials Inter

View full text Add to dashboard Cite

been widely used as the active semiconductor materials for the oxide TFTs. For example, amorphous indium-zinc-tin oxide (a-IZTO) as an active layer on high-k dielectric material such as aluminum oxide (AlO x ), [42][43][44] zirconium oxide (ZrO x ), [45][46][47][48] hafnium oxide (HfO x ), [49] zirconium-doped aluminum oxide (ZAO), [50] and lanthanum doped zirconium oxide (LaZrO x ) [51] have been used for solution process. The purpose of using a high-κ gate insulator is for the low voltage driven oxide TFTs.The oxide TFT could be annealed at a higher temperature (>500 °C) [52] to improve its performance and stability, but higher annealing temperature prevents the use of the plastic substrate for the flexible display. [53] Also, various process technologies are developed to improve the film quality, for example, Ar/O 2 plasma treatment, [54] O 2 annealing, [55] and UV ozone treatment. [56] Many of the previous reports have focused on the thin-film quality and lowering fabrication process temperature by using the UV treatment [57] or combustion method. [58] Moreover, to address present-day microelectronics challenges, the synthesis of high-quality semiconductor precursor solution is essential for high performance, oxide TFTs at low processing temperatures.In this study, we report the impact of metal oxide precursor purification on the performance of TFTs. Smooth surface morphology and the high-quality interface between a-IZTO and ZrO x are confirmed by atomic force microscopy (AFM) and X-ray photoelectron spectroscopic (XPS) analysis, respectively. The mobility, ON/OFF current ratio, gate voltage swing (SS), and hysteresis of the purified a-IZTO TFTs are significantly improved compared to the TFTs using unpurified precursor solutions. The hysteresis and positive bias-stress stability of the transfer curve for the purified a-IZTO TFTs are improved as a result of the reduced interface charge trapping. Therefore, the purification of the oxide semiconductor is an essential step for high performance, solution processed oxide TFTs.

show abstract

Effect of an Ultraviolet-Ozone Treatment on the Electrical Properties of Titanium-Oxide Thin-Film Transistors Fabricated by Using a Sol-Gel Process

Cited by 13 publications

References 32 publications

Removal of Surface Oxygen Vacancies Increases Conductance Through TiO₂ Thin Films for Perovskite Solar Cells

Removal of Surface Oxygen Vacancies Increases Conductance Through TiO₂ Thin Films for Perovskite Solar Cells

Low-Concentration Indium Doping in Solution-Processed Zinc Oxide Films for Thin-Film Transistors

High Performance of a‐IZTO TFT by Purification of the Semiconductor Oxide Precursor

Contact Info

Product

Resources

About

Effect of an Ultraviolet-Ozone Treatment on the Electrical Properties of Titanium-Oxide Thin-Film Transistors Fabricated by Using a Sol-Gel Process

Cited by 13 publications

References 32 publications

Removal of Surface Oxygen Vacancies Increases Conductance Through TiO2 Thin Films for Perovskite Solar Cells

Removal of Surface Oxygen Vacancies Increases Conductance Through TiO2 Thin Films for Perovskite Solar Cells

Low-Concentration Indium Doping in Solution-Processed Zinc Oxide Films for Thin-Film Transistors

High Performance of a‐IZTO TFT by Purification of the Semiconductor Oxide Precursor

Contact Info

Product

Resources

About

Removal of Surface Oxygen Vacancies Increases Conductance Through TiO₂ Thin Films for Perovskite Solar Cells

Removal of Surface Oxygen Vacancies Increases Conductance Through TiO₂ Thin Films for Perovskite Solar Cells