| 著作名稱： | Influence of irradiation atmospheres on the performance of ultraviolet-assisted solution-processed NbZnSn oxide thin film transistors |
| 年度： | 2018 |
| 類別： |
期刊論文
Thin Solid FIlms
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| 摘要： | In this study, we study the influence of ultraviolet (UV) light irradiation [the UV source (254 nm) and the UV-ozone source (6% 185 nm and 94% 254 nm)] and irradiation atmospheres on the characteristics of solution-processed NbZnSn oxide thin film transistors (TFTs). The experimental results indicate the ultraviolet-visible absorption spectrum presents a strong absorption at wavelengths less than 300 nm, implying that the UV source and UV-ozone source can be effectively absorbed by the NbZnSn oxide precursor. From the infrared (IR) spectra, the UV-ozone source illumination can accelerate the reaction of solution processed NbZnSn oxide channels. An improvement of device performance is achieved by the NbZnSn oxide channel layers with UV-ozone source. In addition, we also investigate the effects of the treatment atmosphere (i.e., N2 or O2) on the electrical performance of TFTs. The influence of UV irradiation and irradiation atmospheres on the material properties of NbZnSn oxide channels and electrical characteristics of the NbZnSn oxide devices is also studied. The correlations between the UV treatment and treatment atmospheres on the TFT performance are investigated. |
| 關鍵字： | UV treatment; TFT; ZTO |
| 著作名稱： | Fabrication of solution-processed nitrogen-doped niobium zinc tin oxide thin film transistors using ethanolamine additives |
| 年度： | 2017 |
| 類別： |
期刊論文
Journal of Alloys and Compounds
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| 摘要： | In this study, we fabricated the nitrogen-doped NbZnSnO channel layers by using the sol-gel method. Monoethanolamine (MEA) was used as a nitrogen additive. From the XPS results, the concentration of oxygen vacancies changes as a function of MEA/Nb ratio. A NbZnSnO film with MEA/Nb of 0.2 shows the lowest amount of oxygen vacancies. TFT electrical performance also shows a device with an MEA/Nb ratio of 0.2 possesses a high carrier mobility (7.4 cm2V-1s-1) and good bias stress stability. In addition, we also investigated the effect of the aging time of precursor solution on the electrical characteristics of the TFT. After adding MEA, the annealing temperature of the NbZnSnO channels can be reduced, pertaining to the acceleration of the hydrolysis and condensation reaction. |
| 關鍵字： | Solution process; Monoethanolamine; Thin film transistor; Nitrogen |
| 著作名稱： | Light emission and atomic coordination structure of sol-gel derived erbium-doped SiO2-TiO2 thin films |
| 年度： | 2017 |
| 類別： |
期刊論文
Thin Solid Films
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| 摘要： | Erbium-doped SiO2-TiO2 thin films were prepared by the sol-gel method, using erbium nitrate pentahydrate powder, tetraethyl-orthosilicate (TEOS), and titanium tetraisopropoxide (TTIP) as precursors. The Si/Ti ratios in the SiO2-TiO2 films agree with the TEOS/TTIP molar ratio in the sol-gel precursor. Atomic coordination structure of erbium was defined by extended X-ray absorption fine structure spectrometry (EXAFS) and optical properties of the films were characterized by micro-photoluminescence (Micro-PL). The first-neighbor-shell coordination number of erbium in SiO2-TiO2 thin films would influence the optical properties. The 700oC-annealed 80%SiO2-20%TiO2:Er1.0% (mol%) film with the lowest coordination number exhibits the highest photoluminescence intensity. Moreover, Fourier transform infrared spectroscopy (FTIR) analysis reveals that the main bonding structures of SiO2-TiO2 thin films are related to the erbium dopants. The modification of microstructure and chemical bonding configuration in the SiO2-TiO2 films by the Er-doping concentration and its influence on the optical properties are discussed. |
| 關鍵字： | Sol-gel method; X-ray absorption fine structure spectrometry; Micro-photoluminescence |
| 著作名稱： | The influence of pH value and annealing temperature on the characteristics of ZnO–Ru composite films and their application in thin film transistors |
| 年度： | 2016 |
| 類別： |
期刊論文
Microelectronic Engineering
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| 摘要： | ZnO–Ru thin films were prepared using a sol–gel spin coating method. We investigated the effects of the Rudoping concentration, the pH value of precursor and the annealing temperature on the characteristics of the ZnO–Ru thin films. The crystallinity of ZnO–Ru films decreases as the Ru-concentration increases. The surface morphology of the ZnO–Ru films is also related to the pH of the precursors. The optical energy band gap is a function of Ru-doping concentration and the annealing temperature. The correlations among the Zn/Ru ratio, the pH value of the pre-solutions, the annealing temperature and the characteristics of ZnO–Ru films are derived. In addition to the material properties, the application of ZnO–Ru films as a channel layer in thin film transistors is also discussed. |
| 關鍵字： | thin film transistors, pH value, annealing temperature, ZnO–Ru |
| 著作名稱： | Improvement of transistor characteristics and stability for solutionprocessed ultra-thin high-valence niobium doped zinc-tin oxide thin film transistors |
| 年度： | 2016 |
| 類別： |
期刊論文
Journal of Alloys and Compounds
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| 摘要： | Nb-doped Zinc tin oxide (NZTO) channel materials have been prepared by solution process in combination with the spin-coating method. All NZTO thin film transistors (TFTs) are n-type enhancementmode devices, either without or with Nb additives. High-valence niobium ion (ionic charge ¼ þ5) has a larger ionic potential and similar ionic radius to Zn2þ and Sn4þ ions. As compared with the pure ZTO device, introducing Nb5þ ions into the ZTO channel layers can improve the electrical properties and bias stability of TFTs because of the reduction of the oxygen vacancies. This study discusses the connection among the material properties of the NZTO films and the electrical performance and bias stability of NZTO TFTs and how they are influenced by the Nb/(Nb þ Sn) molar ratios of NZTO films. |
| 關鍵字： | Thin film transistors |
| 著作名稱： | Lithium-Induced Defect Levels in ZnO Nanoparticles To Facilitate Electron Transport in Inverted Organic Photovoltaics |
| 年度： | 2016 |
| 類別： |
期刊論文
The Journal of Physical Chemistry C
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| 摘要： | In this work, lithium-doped zinc oxide nanoparticles (LZO NPs) with different Li/Zn molar ratios (Li/Zn 0, 0.05, 0.2) are successfully prepared to form an electron transporting layer (cathode buffer layer) in the inverted-type P3HT:ICBA organic photovoltaic (OPV) devices. As compared with the undoped ZnO NPs buffer layer, a considerable improvement OPVs from 2.344% to 2.946% is obtained by using 5%-LZO NPs as a buffer layer, which owns Jsc of 7.22 mA/cm2, Voc of 0.86 V, and FF of 47.4%. X-ray absorption near-edge structure (XANES) spectra show the increase of unoccupied O 2p-derived states in 5%-LZO NPs, which leads to better carrier conductance. The energy levels of defects in 5%-LZO NPs analyzed by photoluminescence are found to facilitate electron extraction to the cathode. Impedance measurement results indicate that the carrier lifetime is effectively increased to 2176 μs by applying the 5%-LZO NPs buffer layer, showing the improvement of carrier extraction efficiency and resulting in its progressive performance. |
| 關鍵字： | |
| 著作名稱： | Ambient Constancy of Passivation-Free Ultra-Thin Zinc Tin Oxide Thin Film Transistor |
| 年度： | 2015 |
| 類別： |
期刊論文
ECS Solid State Letters
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| 摘要： | An ultra-thin (5 nm-thick), unpassivated zinc tin oxide (ZTO) thin-film transistor TFT, fabricated with solution process, exhibits a good field-effect mobility (13 ∼ 14 cm2/Vs), small subthreshold swing (∼0.30 V/dec.) and high on/off current ratio (∼108). The field-effect mobility can be further enhanced by increasing the ZTOthickness to 12 nm and 22 nm. Furthermore, ID-VG characteristics of the 5 nm-thick ZTO TFT remain unaffected, regardless of working in air (60% relative humidity), vacuum or dry O2 atmosphere. The dissimilar TFT characteristics are discussed in terms of oxygen deficiency content, as well as the Fermi level position (EF to EC) for ZTO of various thicknesses to explain the moisture immunity of the 5 nm-thick solution-processed ZTO TFT. |
| 關鍵字： | Thin Film Transistor, Solution process, Zinc tin oxide |
| 著作名稱： | Role of oxygen vacancies on the bias illumination stress stability of solution-processed zinc tin oxide thin film transistors |
| 年度： | 2014 |
| 類別： |
期刊論文
Applied Physics Letters
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| 摘要： | Solution-processed ultra-thin (?3 nm) zinc tin oxide (ZTO) thin film transistors (TFTs) with a mobility of 8 cm2/Vs are obtained with post spin-coating annealing at only 350 °C. The effect of light illumination (at wavelengths of 405 nm or 532 nm) on the stability of TFT transfer characteristics under various gate bias stress conditions (zero, positive, and negative) is investigated. It is found that the ΔVth (Vthstress 3400 s ? stress 0 s) window is significantly positive when ZTO TFTs are under positive bias stress (PBS, ΔVth 9.98 V) and positive bias illumination stress (λ 405 nm and ΔVth 6.96 V), but ΔVth is slightly negative under only light illumination stress (λ 405 nm and ΔVth ?2.02 V) or negative bias stress (ΔVth ?2.27 V). However, the ΔVth of ZTO TFT under negative bias illumination stress is substantial, and it will efficiently recover the ΔVth caused by PBS. The result is attributed to the photo-ionization and subsequent transition of electronic states of oxygen vacancies (i.e., Vo, Vo+, and Vo++) in ZTO. A detailed mechanism is discussed to better understand the bias stress stability of solution processed ZTO TFTs.
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| 關鍵字： | |
| 著作名稱： | High carrier mobility and electrical stability under negative bias illumination stress of ZnO thin-film transistors with N2O plasma treated HfOx gate dielectrics |
| 年度： | 2013 |
| 類別： |
期刊論文
JOURNAL OF APPLIED PHYSICS
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| 摘要： | ZnO thin-film transistors (TFTs) using high-k hafnium oxide (HfO)x as the gate dielectrics achieve a low operating voltage of below 1V. A negative threshold voltage shift of devices was observed after the negative bias illumination stress (NBIS) from a 635 nm laser. Plasma treatment of the HfOx dielectric surface using different gases (i.e., N2O and O2) was used to improve the TFTs’ electrical stability. By calculating the subthreshold swing and analyzing the oxygen chemical bonding states nearby the ZnO/HfOx interface by x-ray photoelectron spectroscopy, we found that the interface trapped state and oxygen vacancies existed in ZnO active layer caused this unstable performance. The stability of ZnO TFTs is improved with using N2O plasma-treated HfOx dielectric, as this eliminate the defect in the ZnO layer. |
| 關鍵字： | carrier mobility, negative bias illumination stress, and Thin Film Transistor |
| 著作名稱： | Effects of oxygen plasma treatment on the on/off current ratio and stability of ZnO thin film transistors |
| 年度： | 2017 |
| 類別： |
期刊論文
Academia Journal of Scientific Research
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| 摘要： | Thin-film transistors (TFTs) using ZnO as the active semiconductor and SiO2 as the dielectric were fabricated on Si substrates. Oxygen plasma treatment is applied on ZnO or SiO2 surface to investigate its effects on the electrical performance of TFTs. As compared to the TFT device with oxygen plasma applied on the ZnO surface, the TFT device subject to oxygen plasma treatment on the SiO2 surface exhibits a reduced off current and improved on/off current ratio. X-ray photoelectron spectroscopy analysis reveals that more complete Zn-O bondings in the ZnO film nearby the dielectric should contribute to the reduced off current and enhanced on/off current ratio of the O2 plasma treated SiO2 TFT device. The relation between electrical bias stress stability and plasma treatment is also discussed in this work. |
| 關鍵字： | Thin-film transistors (TFTs); ZnO; SiO2. |