Structural, optical and electrical properties of Hf-doped ZnO transparent conducting films prepared by sol–gel method

Wang, Fenggui; Zhao, Xiaoru; Duan, Libing; Wang, Yajun; Niu, Hongru; Ali, Anwar

doi:10.1016/j.jallcom.2014.10.117

Cited by 20 publications

(15 citation statements)

References 32 publications

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“…HfO bonds even at a relatively low temperature (170°C) compared to other techniques [34][35]. The cyclic measurements for Seebeck coefficients at low T, on the other hand, remained constant for all samples throughout the temperature range, as shown in Fig.…”

Section: Effect Of Doping Element On the Thermoelectric Performancementioning

confidence: 65%

Enhanced Thermoelectric Transport and Stability in Atomic Layer Deposited-HfO₂/ZnO and TiO₂/ZnO-Sandwiched Multilayer Thin Films

Felizco

Juntunen

Uenuma

et al. 2020

ACS Appl. Mater. Interfaces

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Herein, enhancements in thermoelectric performance, both power factor and thermal stability, are exhibited by sandwiching HfO 2 and TiO 2 layers onto atomic layer deposited ZnO thin films. High temperature thermoelectric measurements from 300 to 450 K revealed an almost two-fold improvement in electrical conductivity for TiO 2 /ZnO (TZO) samples, primarily owing to increase in carrier concentration by Ti doping. On the other hand, HfO 2 /ZnO (HZO) achieved the highest power factor values owing to maintaining Seebeck coefficients comparable to pure ZnO. HZO also exhibited excellent stability after multiple thermal cycles, which has not been previously observed for pure or doped ZnO thin films. Such improvement in both thermoelectric properties and thermal stability of HZO can be attributed to a shift in crystalline orientation from a-axis to c-axis, as well as the high bond dissociation energy of HfO, stabilizing the ZnO structure. These unique properties exhibited by ALD HZO and TZO thin films pave the way for next generation transparent thermoelectric devices.

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Section: Effect Of Doping Element On the Thermoelectric Performancementioning

confidence: 65%

Enhanced Thermoelectric Transport and Stability in Atomic Layer Deposited-HfO₂/ZnO and TiO₂/ZnO-Sandwiched Multilayer Thin Films

Felizco

Juntunen

Uenuma

et al. 2020

ACS Appl. Mater. Interfaces

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“…The recent research report findings indicate that the high quality ZnO thin film could be synthesized by various techniques such as sol-gel method, radio frequency magnetron sputtering, metal organic chemical vapor deposition (MOCVD), and so on [9][10][11][12][13][14] . Each technique has its advantages and disadvantages.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of High c-axis ZnO Thin Film by Plasma Enhanced Chemical Vapor Deposition System and its UV Photodetector Application

Chao

Wei

2015

JoVE

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In this study, zinc oxide (ZnO) thin films with high c-axis (0002) preferential orientation have been successfully and effectively synthesized onto silicon (Si) substrates via different synthesized temperatures by using plasma enhanced chemical vapor deposition (PECVD) system. The effects of different synthesized temperatures on the crystal structure, surface morphologies and optical properties have been investigated. The X-ray diffraction (XRD) patterns indicated that the intensity of (0002) diffraction peak became stronger with increasing synthesized temperature until 400 (o)C. The diffraction intensity of (0002) peak gradually became weaker accompanying with appearance of (10-10) diffraction peak as the synthesized temperature up to excess of 400 (o)C. The RT photoluminescence (PL) spectra exhibited a strong near-band-edge (NBE) emission observed at around 375 nm and a negligible deep-level (DL) emission located at around 575 nm under high c-axis ZnO thin films. Field emission scanning electron microscopy (FE-SEM) images revealed the homogeneous surface and with small grain size distribution. The ZnO thin films have also been synthesized onto glass substrates under the same parameters for measuring the transmittance. For the purpose of ultraviolet (UV) photodetector application, the interdigitated platinum (Pt) thin film (thickness ~100 nm) fabricated via conventional optical lithography process and radio frequency (RF) magnetron sputtering. In order to reach Ohmic contact, the device was annealed in argon circumstances at 450 (o)C by rapid thermal annealing (RTA) system for 10 min. After the systematic measurements, the current-voltage (I-V) curve of photo and dark current and time-dependent photocurrent response results exhibited a good responsivity and reliability, indicating that the high c-axis ZnO thin film is a suitable sensing layer for UV photodetector application.

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“…However, for higher doping (5 at%), the bandgap decreased, probably due to lattice distortion. Doping with Hf 4+ , Ta 5+ , and Zr 4+ may lead to an increase of the bandgap, as the respective oxides have higher bandgap than In 2 O 3 , HfO 2 (5.25-5.90 eV) [34,35], Ta 2 O 5 (3.8-5.3 eV) [36], and ZrO 2 (4.3-5.5 eV) [37][38][39]. Solution-based TCOs have been reported using different dopants as detailed in Table 1.…”

Section: Introductionmentioning

confidence: 99%

Solution Combustion Synthesis of Hafnium-Doped Indium Oxide Thin Films for Transparent Conductors

et al. 2022

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Indium oxide (In2O3)-based transparent conducting oxides (TCOs) have been widely used and studied for a variety of applications, such as optoelectronic devices. However, some of the more promising dopants (zirconium, hafnium, and tantalum) for this oxide have not received much attention, as studies have mainly focused on tin and zinc, and even fewer have been explored by solution processes. This work focuses on developing solution-combustion-processed hafnium (Hf)-doped In2O3 thin films and evaluating different annealing parameters on TCO’s properties using a low environmental impact solvent. Optimized TCOs were achieved for 0.5 M% Hf-doped In2O3 when produced at 400 °C, showing high transparency in the visible range of the spectrum, a bulk resistivity of 5.73 × 10−2 Ω.cm, a mobility of 6.65 cm2/V.s, and a carrier concentration of 1.72 × 1019 cm−3. Then, these results were improved by using rapid thermal annealing (RTA) for 10 min at 600 °C, reaching a bulk resistivity of 3.95 × 10 −3 Ω.cm, a mobility of 21 cm2/V.s, and a carrier concentration of 7.98 × 1019 cm−3, in air. The present work brings solution-based TCOs a step closer to low-cost optoelectronic applications.

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Structural, optical and electrical properties of Hf-doped ZnO transparent conducting films prepared by sol–gel method

Cited by 20 publications

References 32 publications

Enhanced Thermoelectric Transport and Stability in Atomic Layer Deposited-HfO₂/ZnO and TiO₂/ZnO-Sandwiched Multilayer Thin Films

Enhanced Thermoelectric Transport and Stability in Atomic Layer Deposited-HfO₂/ZnO and TiO₂/ZnO-Sandwiched Multilayer Thin Films

Synthesis and Characterization of High c-axis ZnO Thin Film by Plasma Enhanced Chemical Vapor Deposition System and its UV Photodetector Application

Solution Combustion Synthesis of Hafnium-Doped Indium Oxide Thin Films for Transparent Conductors

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Structural, optical and electrical properties of Hf-doped ZnO transparent conducting films prepared by sol–gel method

Cited by 20 publications

References 32 publications

Enhanced Thermoelectric Transport and Stability in Atomic Layer Deposited-HfO2/ZnO and TiO2/ZnO-Sandwiched Multilayer Thin Films

Enhanced Thermoelectric Transport and Stability in Atomic Layer Deposited-HfO2/ZnO and TiO2/ZnO-Sandwiched Multilayer Thin Films

Synthesis and Characterization of High c-axis ZnO Thin Film by Plasma Enhanced Chemical Vapor Deposition System and its UV Photodetector Application

Solution Combustion Synthesis of Hafnium-Doped Indium Oxide Thin Films for Transparent Conductors

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Enhanced Thermoelectric Transport and Stability in Atomic Layer Deposited-HfO₂/ZnO and TiO₂/ZnO-Sandwiched Multilayer Thin Films

Enhanced Thermoelectric Transport and Stability in Atomic Layer Deposited-HfO₂/ZnO and TiO₂/ZnO-Sandwiched Multilayer Thin Films