Structure and properties of GZO thin films grown on ZnO buffer layers

Chu, Cheng-Jye; Huang, C.H.; Kao, Li-Heng; Chou, Chang‐Pin; Hsu, Cheng-Ying; Chen, C.W.; Chen, D.Y.

doi:10.1016/j.spmi.2010.12.001

Cited by 5 publications

(3 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, Yamada et al [17] reported that the lowest electrical resistivity of 2.1 × 10 −4 Ω·cm can be achieved at the substrate temperature of 250°C for the GZO thin films prepared by ionplating method with DC arc discharge, while Nam et al [16] found the lowest electrical resistivity to be about 1.5 × 10 −3 Ω·cm for the GZO film grown at 300°C by thermal atomic layer deposition. Furthermore, many authors adopted Taguchi method to investigate the effect of various deposition conditions on structure and optoelectronic properties of the GZO thin films, and found that the substrate temperature is one of the most important deposition parameters determining the film properties [18][19][20]. To our knowledge, although many experimental studies have been conducted on the synthesis, structural and optoelectrical properties of the GZO thin films, there are no detailed studies on optical constants and their dispersion behaviour, which are crucial to the structure design and performance improvement of optoelectronic devices.…”

Section: Introductionmentioning

confidence: 99%

Preparation, structure and optical properties of transparent conducting gallium-doped zinc oxide thin films

Long

et al. 2015

Materials Science-Poland

View full text Add to dashboard Cite

Highly conductive gallium-doped zinc oxide (GZO) transparent thin films were deposited on glass substrates by RF magnetron sputtering. The deposited films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), four-point probe and UV-Vis spectrophotometer, respectively. The effect of growth temperature on the structure and optoelectrical properties of the films was investigated. The results demonstrate that high quality GZO films oriented with their crystallographic c-axis perpendicular to the substrates are obtained. The structure and optoelectrical properties of the films are highly dependent on the growth temperature. It is found that with increasing growth temperature, the average visible transmittance of the deposited films is enhanced and the residual stress in the thin films is obviously relaxed. The GZO films deposited at the growth temperature of 400°C, which have the largest grain size (74.3 nm), the lowest electrical resistivity (1.31 × 10 −3 Ω·cm) and the maximum figure of merit (1.46 × 10 −2 Ω −1 ), exhibit the best optoelectrical properties. Furthermore, the optical properties of the deposited films were determined by the optical characterization methods and the optical energy-gaps were evaluated by extrapolation method. A blue shift of the optical energy gap is observed with an increase in the growth temperature.

show abstract

Section: Introductionmentioning

confidence: 99%

Preparation, structure and optical properties of transparent conducting gallium-doped zinc oxide thin films

Long

et al. 2015

Materials Science-Poland

View full text Add to dashboard Cite

show abstract

“…In grey system theory, the grey-relational analysis is a measurement method to analyze the relationship between sequences using less data and multifactor, which is considered more helpful to the statistical regression analysis. There are few papers concerning the examination on properties of ZnO thin films by using grey-relational Taguchi method [20][21][22]. However, there is no related research concerning grey-relational Taguchi method to design the processing parameters for depositing ZnO thin films by using CAPD.…”

Section: Introductionmentioning

confidence: 99%

Optimization of the Cathode Arc Plasma Deposition Processing Parameters of ZnO Film Using the Grey-Relational Taguchi Method

Hsu

Chou

Fang

et al. 2014

Advances in Materials Science and Engineering

View full text Add to dashboard Cite

We deposited undoped ZnO films on the glass substrate at a low temperature (<70 ∘ C) using cathode arc plasma deposition (CAPD) and the grey-relational Taguchi method was used to determine the processing parameters of ZnO thin films. The Taguchi method with an L9 orthogonal array, signal-to-noise ( / ) ratio, and analysis of variance (ANOVA) is employed to investigate the performances in the deposition operations. The effect and optimization of deposition parameters, comprising the Ar : O 2 gas flow ratio of 1 : 6, 1 : 8, and 1 : 10, the arc current of 50 A, 60 A, and 70 A, and the deposition time of 5 min, 10 min, and 15 min, on the electrical resistivity and optical transmittance of the ZnO films are studied. The results indicate that, by using the grey-relational Taguchi method, the optical transmittance of ZnO thin films increases from 88.17% to 88.82% and the electrical resistivity decreases from 5.12 × 10 −3 Ω-cm to 4.38 × 10 −3 Ω-cm, respectively.

show abstract

“…Several reports have suggested that a GZO/ZnO buffer structure could enhance TCO properties by reducing the film roughness and improving crystallization. 9 To our best knowledge, there has been only one study on GZO film deposited on flexible substrates with a buffer layer using the radio-frequency (RF) sputter deposition method. Gong et al reported that the configuration of GZO/ZnO on polycarbonate (PC) substrates could be realized and that the optimal parameters of the ZnO buffer layer could be obtained according to the Taguchi experimental design.…”

mentioning

confidence: 99%

Effects of ZnO Buffer Layer on Characteristics of ZnO:Ga Films Grown on Flexible Substrates: Investigation of Surface Energy, Electrical, Optical, and Structural Properties

Lin

Chen

et al. 2013

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

Ga-doped ZnO (GZO) transparent conductive oxide thin films were deposited on flexible polyethersulphone (PES) substrates by radiofrequency sputtering at room temperature. With the addition of an optimized 100-nm-thick ZnO buffer layer, the transmittance, carrier concentration, Hall mobility, and resistivity of GZO films improved from 88.3 to 94.45%, −2.89 × 10 21 to −3.39 × 10 21 cm −3 , 1.76 to 7.97 cm 2 /V-s, and 1.32 × 10 −3 to 2.201 × 10 −4 -cm, respectively. The higher surface energy (49.85 mJ/m 2 ) of the 100-nm-thick ZnO layer deposited on the PES substrate compared to those of a bare PES substrate and ZnO layers of other thicknesses deposited on PES substrates is likely responsible for the superior GZO quality obtained with the GZO/100-nm-thick ZnO buffer/PES structure. Moreover, the best adhesion at the GZO surface was observed for the GZO/100-nm-thick ZnO buffer/PES structure based on it having the highest surface energy (67.33 mJ/m 2 ). The GZO/100-nm-thick ZnO buffer/PES structure thus has potential to replace the GZO/PES structure for use in flexible transparent optoelectronic devices.Transparent conductive oxide (TCO) thin films have a high carrier concentration, high mobility, and low resistivity in the visible light region, and are thus widely used for organic light-emitting diodes (OLEDs), 1 solar cells, 2 oxide thin-film transistors, 3 memory devices, 4 and touch panels. 5 Among TCO films, indium tin oxide (ITO) is widely used for industry applications due to its excellent resistivity (ρ ∼ 1 × 10 −4 -cm) and high transparency (about 85% in the visible region). However, indium is expensive and toxic. IIIA-elementdoped ZnO, such as ZnO:Al 6 and ZnO:Ga, 7,8 has been found to be a promising material to replace ITO because of its lower cost, lower deposition temperature, and lower toxicity. Compared to the covalent bond length of Zn-O, the variations in the covalent bond length of Al-O and Ga-O are 0.13 and 0.05 Å, respectively, and thus GZO has a smaller lattice deformation than that of AZO. Additionally, Ga is less reactive to oxidation than Al during the deposition. 7 Therefore, GZO is more suitable than AZO to replace ITO.Compared with glass substrates, flexible substrates have a rougher surface, and thus higher resistivity. It is known that the resistivity of flexible-substrate-based devices can be lowered by utilizing a GZO/metal/GZO structure. However, this structure increases the cost of the deposition process. Several reports have suggested that a GZO/ZnO buffer structure could enhance TCO properties by reducing the film roughness and improving crystallization. 9 To our best knowledge, there has been only one study on GZO film deposited on flexible substrates with a buffer layer using the radio-frequency (RF) sputter deposition method. Gong et al. reported that the configuration of GZO/ZnO on polycarbonate (PC) substrates could be realized and that the optimal parameters of the ZnO buffer layer could be obtained according to the Taguchi experimental design. 10 The lowest electrical resistivi...

show abstract

Structure and properties of GZO thin films grown on ZnO buffer layers

Cited by 5 publications

References 24 publications

Preparation, structure and optical properties of transparent conducting gallium-doped zinc oxide thin films

Preparation, structure and optical properties of transparent conducting gallium-doped zinc oxide thin films

Optimization of the Cathode Arc Plasma Deposition Processing Parameters of ZnO Film Using the Grey-Relational Taguchi Method

Effects of ZnO Buffer Layer on Characteristics of ZnO:Ga Films Grown on Flexible Substrates: Investigation of Surface Energy, Electrical, Optical, and Structural Properties

Contact Info

Product

Resources

About