• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.421.1-421.1
• /
• 2016

We studied indium-doped zinc oxide (IZO) film grown by atomic layer deposition (ALD) as transparent conductive oxide (TCO). A variety of TCO layer, such as ZnO:Al (AZO), InSnO2(ITO), Zn (O,S) etc, has been grown by various method, such as ALD, chemical vapor deposition (CVD), sputtering, laser ablation, sol-gel technique, etc. Among many deposition methods, ALD has various advantages such as uniformity of film thickness, film composition, conformality, and low temperature deposition, as compared with other techniques. In this study, we deposited indium-doped zinc oxide thin films using diethyl[bis(trimethylsilyl)amido]indium [Et2InN(TMS)2] as indium precursor, DEZn as zinc precursor and H2O as oxidant for ALD and investigated the optical and electrical properties of IZO films. As an alternative, this liquid In precursor would has several advantages in indium oxide thin-film processes by ALD, especially for low resistance indium oxide thin film and high deposition rate as compared to InCp, InCl3, TMIn precursors etc. We found out that Indium oxide films grown by Et2InN(TMS)2 and H2O precursor show ALD growth mode and ALD growth window. We also found out the different growth rate of Indium oxide as the substrate and investigated the effect of the substrate on Indium oxide growth.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.06a
• /
• pp.183-183
• /
• 2009

본 연구에선 ITO에 사용되는 Indium의 양을 줄이기 위해 ITO와 유사한 성질을 보이는 조성인 Indium - Zinc - Tin Turnary compound를 연구하였다. 각 조성은 Indium - Zinc - Tin Turnary compound를 기본으로 하여 Zinc site에 이종원소인 Al2O3와 Ga2O3를 doping함에 따라 변화되는 전기적 특성을 살며보았다. 분석에 사용한 Ceramic pellet은 일반적인 Ceramic process를 거쳐 제작되었다. 각 조성의 전기적 특성은 TCR meter와 Hall effect analyser를 이용하여 측정하였고, X-ray diffraction measurements(XRD), Scanning Electron microscope(SEM)를 이용하여 결정학적 특성을 분석하였다.

• Transactions on Electrical and Electronic Materials
• /
• v.17 no.1
• /
• pp.33-36
• /
• 2016

In the present work, a Ni-doped indium zinc oxide (NIZO) film and its multilayers with Ag layers were investigated as transparent conducting electrodes for liquid crystal display (LCD) applications, as a substitute for indium tin oxide (ITO) electrodes. By interposing the Ag layer between the NIZO layers, the loss of the optical transmittance occurred; however, the Ag layer brought enhancement of electrical sheet resistance to the NIZO/Ag/NIZO multilayer electrode. The twisted nematic cell based on the NIZO/Ag/NIZO multilayer electrode exhibited superior electro-optical characteristics than those based on single NIZO electrode and was competitive compared to those based on the conventional ITO electrode. An LCD-based NIZO/Ag/NIZO multilayer electrode may allow new approaches to conventional ITO electrodes in display technology.

• Advances in nano research
• /
• v.2 no.4
• /
• pp.179-186
• /
• 2014

Indium-nitrogen co-doped zinc oxide thin films (INZO) were prepared on glass substrates in the atmosphere by ultrasonic spray pyrolysis. The aqueous solution of zinc acetate, ammonium acetate and different indium sources: indium (III) chloride and indium (III) nitrate were used as the precursors. After film deposition, different anneal temperature treatment as 350, 450, $550^{\circ}C$ were applied. Electrical properties as concentration and mobility were characterized by Hall measurement. The surface morphology and crystalline quality were characterized by SEM and XRD. With the activation energy analysis for both films, the concentration variation of the films at different heat treatment temperature was realized. Donors correspond to zinc related states dominate the conduction mechanism for these INZO films after $550^{\circ}C$ high temperature heat treatment process.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.2
• /
• pp.494-500
• /
• 2014

Indium-doped zinc oxide nanocrystals (IZO NCs), capped with stearic acid (SA) of different sizes, were synthesized using a hot injection method in a noncoordinating solvent 1-octadecene (ODE). The ligand exchange process was employed to modify the surface of IZO NCs by replacing the longer-chain ligand of stearic acid with the shorter-chain ligand of butylamine (BA). It should be noted that the ligand-exchange percentage was observed to be 75%. The change of particle size, morphology, and crystal structures were obtained using a field emission scanning electron microscope (FE-SEM) and X-ray diffraction pattern results. In our study, the 5 nm and 10 nm IZO NCs capped with stearic acid (SA-IZO) were ligand-exchanged with butylamine (BA), and were then spin-coated on a thermal oxide ($SiO_2$) gate insulator to fabricate a thin film transistor (TFT) device. The films were then annealed at various temperatures: $350^{\circ}C$, $400^{\circ}C$, $500^{\circ}C$, and $600^{\circ}C$. All samples showed semiconducting behavior and exhibited n-channel TFT. Curing temperature dependent on mobility was observed. Interestingly, mobility decreases with the increasing size of NCs from 5 to 10 nm. Miller-Abrahams hopping formalism was employed to explain the hopping mechanism insight our IZO NC films. By focusing on the effect of size, different curing temperatures, electron coupling, tunneling rate, and inter-NC separation, we found that the decrease in electron mobility for larger NCs was due to smaller electronic coupling.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.187-187
• /
• 2012

Solution-processed metal-alloy oxides such as indium zinc oxide (IZO), indium gallium zinc oxide (IGZO) has been extensively researched due to their high electron mobility, environmental stability, optical transparency, and solution-processibility. In spite of their excellent material properties, however, there remains a challenging problem for utilizing IZO or IGZO in electronic devices: the supply shortage of indium (In). The cost of indium is high, what is more, indium is becoming more expensive and scarce and thus strategically important. Therefore, developing an alternative route to improve carrier mobility of solution-processable ZnO is critical and essential. Here, we introduce a simple route to achieve high-performance and low-temperature solution-processed ZnO thin film transistors (TFTs) by employing alkali-metal doping such as Li, Na, K or Rb. Li-doped ZnO TFTs exhibited excellent device performance with a field-effect mobility of $7.3cm^2{\cdot}V-1{\cdot}s-1$ and an on/off current ratio of more than 107. Also, in case of higher drain voltage operation (VD=60V), the field effect mobility increased up to $11.45cm^2{\cdot}V-1{\cdot}s-1$. These all alkali metal doped ZnO TFTs were fabricated at maximum process temperature as low as $300^{\circ}C$. Moreover, low-voltage operating ZnO TFTs was fabricated with the ion gel gate dielectrics. The ultra high capacitance of the ion gel gate dielectrics allowed high on-current operation at low voltage. These devices also showed excellent operational stability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.260-261
• /
• 2008

In this study, we investigated the properties of Indium Zinc Oxide (IZO) films prepared in facing targets sputtering (FTS) system at room temperature as function of oxygen contents. As as-deposited films were rapidly thermal annealing on air atmosphere of $400^{\circ}C$ for 30s. As a result, the transmittance of IZO films increased with increasing oxygen flow in the visible range. After rapidly thermal annealing to films, the optical properties of films improved than films deposited at R.T, but the electrical properties decreased. Before RTA treatment, the lowest resistivity IZO is $5.4\times10^{-4}[\Omega{\cdot}cm]$ at oxygen gas flow. But, after RTA treatment, IZO films have the value of lowest resistivity at the lower oxygen gas ratio in compare with before RTA treatment. The resistivity of IZO films is $7.29\times10^{-4}[\Omega{\cdot}cm]$ at pure argon atmosphere.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.8
• /
• pp.711-715
• /
• 2007

Properties of organic light-emitting diodes (OLEDs) with aluminum-doped zinc oxide (ZnO:Al) anodes showed different behaviors from OLEDs with indium tin oxide (ITO) anodes according to driving conditions. OLEDs with ITO anodes gave higher current density and luminance in lower voltage region and better EL and power efficiency under lower current density conditions, However, OLEDs with ZnO:Al anodes gave higher current density and luminance in higher voltage region over about 8V and better EL and power efficiency under higher current density over $200mA/cm^2$. These seemed to be due to the differences in conduction properties of semiconducting ZnO:Al and metallic ITO. OLEDs with ZnO:Al anodes showed nearly saturated efficiency under high current driving conditions compared with those of OLEDs with ITO anodes. This meant better charge balance in OLEDs with ZnO:Al anodes. These properties of OLEDs with ZnO:Al anodes are useful in making bright display devices with efficiency.

• New & Renewable Energy
• /
• v.17 no.1
• /
• pp.1-6
• /
• 2021

Transparent conducting oxide (TCO) films have been widely used in optoelectronic devices, such as OLEDs, TFTs, and solar cells. However, thin films of indium tin oxide (ITO) have few disadvantages pertaining to process parameters such as substrate temperature and sputtering power. In this study, we investigated the requirements for using TCO films in silicon-based solar cells and the best alternative TCO materials to improve their efficiency. Moreover, we discussed the current status of high-efficiency solar cells using low-temperature TCO films such as indium zinc oxide and Zr-doped indium oxide.

• Journal of the Korean institute of surface engineering
• /
• v.43 no.4
• /
• pp.194-198
• /
• 2010

Indium doped zinc oxide films (ZIO) were deposited on non-alkali glass substrates by radio frequency (RF) magnetron sputtering at room temperature. The structural, electrical and optical properties of the ZIO films were investigated as a function of their $In_2O_3$ content (3.33-15.22 wt%). The ZIO films deposited with an $In_2O_3$ content of 9.54 wt% showed a relatively low resistivity of $9.13{\times}10^{-4}{\Omega}cm$ and a highly c-axis preferred orientation. The grain size and FWHM were mainly affected by the $In_2O_3$ content. The crystallinity and resistivity were enhanced with increasing grain size. The average transmittance of the ZIO films was over 85% in the visible region and their band gap varied from 3.22 to 3.66 eV depending on their doping ratio.