Modulation of the dissipation factor in transparent AlZnO/ZrO2/AlZnO capacitors

Zhang, Guozhen; Wu, Hao; Wang, Xiao; Zhang, Daxiao; Wang, Ti; Liu, Chang

doi:10.1016/j.jallcom.2016.08.207

Cited by 9 publications

(8 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The capacitance density declined slightly when the voltage swept from −1 to 1 V. The possible reason may be that ZrO 2 films deposited at a relatively low temperature (150 °C) contain more impurities due to incomplete chemical reaction between TDMAZr and H 2 O. When the ZrO 2 films were grown at 200 °C, the chemical reaction was more sufficient and the capacitance maintained almost invariant in a wider voltage range from −2 to 2 V, as can be seen from our recent work . However, the PEN substrate cannot bear 200 °C heating, and we tried to grow ZrO 2 films at up limit temperature of 150 °C.…”

Section: Resultsmentioning

confidence: 90%

See 1 more Smart Citation

Fully Transparent and Flexible Capacitors with ZrO₂ as the Dielectric Layer

Zhang

Guo

et al. 2018

Adv Elect Materials

Self Cite

View full text Add to dashboard Cite

which opens the door to applications on flexible substrates. However, the surface hydrophobicity of plastic substrates remains a big obstacle that inhibits the initial nucleation for the ALD growth process. To solve this problem, an AZO buffer layer can be introduced on plastic substrates. Such a layer can be prepared via multiple physical methods, such as magnetron sputtering, [11] electron beam evaporation, [12] or pulsed laser deposition. [13] Different from chemical deposition methods, the physical deposition usually leads to a denser film without the basic requirements of the hydroxyl groups absorbed on the plastic surface. Here, we selected sputtering method because it is cheap and convenient. Unfortunately, the AZO films sputtered at low temperatures usually have a large sheet resistance and are not suitable to serve as the electrodes of capacitors. Hence, it is necessary to deposit an ALD-AZO layer on the sputtered-AZO film to improve the overall conductivity. To further improve the flexibility and conductivity, silver nanowires (AgNWs) have been added into AZO films to form the composite AZO/AgNWs/AZO electrodes which showed a very low sheet resistance below 10 Ω, as can be seen from our previous work. [14] In terms of dielectrics, high-k materials have always been regarded as promising candidates for transparent electronics because most of them have wide bandgaps. Capacitors with large capacitance, small featured size, and low power consumption can be realized by employing high-k materials as dielectrics. Many high-k materials including Al 2 O 3 , [15] TiO 2 , [16] HfO 2 , [17] and ZrO 2 [18] have been widely investigated during the past few years. Among them, ZrO 2 demonstrated a great potential due to its high permittivity of about 25 and a relatively large bandgap of about 5.6 eV. [19] In addition, its excellent temperature stability and low permeation rates for ambient gases are attractive to improve the device reliability. [20,21] In our recent work, the AZO/ ZrO 2 /AZO capacitors showed an ultralow leakage current while maintaining a large capacitance density. [22] In this work, transparent and flexible capacitors were directly fabricated on polyethylene naphthalate (PEN) substrates. The capacitors showed a relatively large capacitance density and an ultralow leakage current. Capacitors with and without AgNWs embedded in the AZO bottom electrode can both work normally under an outward bending radius of 7 mm. However, capacitors with the composite AZO/AgNWs/AZO electrodes showed superior antifatigue properties than capacitors with the ordinary AZO electrodes without AgNWs.Transparent and flexible capacitors with ZrO 2 as the dielectric layer are fabricated directly on polyethylene naphthalate (PEN) substrates by an in situ atomic layer deposition method. The hybrid AlZnO and silver nanowires serve as the bottom electrode. The capacitors exhibit a high capacitance density of 15.2 fF µm −2 and an ultralow leakage current (1.0 × 10 −9 A cm −2 at 1 V). Bending tests reveal that the capacitors can be ou...

show abstract

Section: Resultsmentioning

confidence: 90%

“…In addition, its excellent temperature stability and low permeation rates for ambient gases are attractive to improve the device reliability . In our recent work, the AZO/ZrO 2 /AZO capacitors showed an ultralow leakage current while maintaining a large capacitance density …”

Section: Introductionmentioning

confidence: 99%

Fully Transparent and Flexible Capacitors with ZrO₂ as the Dielectric Layer

Zhang

Guo

et al. 2018

Adv Elect Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…This is because, we know, for parallel circuit, the loss tangent or dissipation factor is inversely proportional to the parallel resistance which increases with the thickness of the film. 49 It is important to note here that, at 10 kHz frequency, the optimally cured ZrO 2 film (cured with 20 pulses) exhibits a low dissipation factor value of ∼0.05.…”

Section: Resultsmentioning

confidence: 99%

Photonic Cured Metal Oxides for Low-Cost, High-Performance, Low-Voltage, Flexible, and Transparent Thin-Film Transistors

Sarkar

Maji

Khan

et al. 2022

ACS Appl. Electron. Mater.

View full text Add to dashboard Cite

Flash light-based photonic curing has recently emerged as a promising technique for low-cost and ultrafast production of flexible electronics. In this work, we demonstrate photonic curing-based low-cost fabrication of ZrO 2based high-k dielectric and ZnO-based semiconducting layers for low-voltage, high-performance, flexible, and transparent thin-film transistors (TFTs). Such metal oxide-based devices are extremely important to realize next-generation technologies with high power efficiency, optical transparency,mecahnical flexibility, high reliability, and environmental stability. In the current work, photonic cured ZrO 2 and ZnO layers were obtained by exposing their spin-coated precursor solutions to the high-energy pulsed light of a xenon flash lamp. The numbers of applied pulses were varied for optimization. Hence, the optimally cured ZrO 2 film exhibited excellent dielectric property with high areal capacitance of ∼485 nFcm −2 , low leakage current density of 10 −4 A cm −2 , and high breakdown strength of ∼2.3 MV cm −1 which further enabled the low-voltage operation (< 3 V) for the fabricated TFTs. On the other hand, the optimally cured ZnO layer resulted in the high performance for the TFTs with field-effect mobility of 3.4 ± 0.1 cm 2 V −1 s −1 , on−off ratio of 3.3 ± 0.8 × 10 5 , and threshold voltage of 0.8 ± 0.03 V. The mechanical flexibility of these devices was demonstrated by showing their operational stability under mechancial bending and after continuous bending cycles. These devices also exhibited optical transparency up to 80% in the visible wavelength range. To explain the behavior of these photonic cured layers and devices under different process conditions, several microscopic and spectroscopic studies were performed. Finally, the ultraviolet−visible absorption spectroscopy and a finite element simulation study also showed the viability of photonic curing to successfully fabricate solution-derived ZnO and ZrO 2 layers on a flexible substrate.

show abstract

“…8 Noteworthy reviews exist on the topic which explore the fundamentals and importance of these materials [8][9][10] and also with a focus on specific application fields. 11 The applications of hybrid films are almost endless, ranging from use as capacitors, [12][13][14][15] dielectrics and insulators, [16][17][18][19][20][21][22][23][24][25] encapsulation layers/protective coatings, [26][27][28][29][30][31][32][33][34] lubricants 35 and optical waveguides. 36 Specifically, nanolaminates are multicomponent systems consisting of alternating layers of materials such as metals and metal oxides.…”

Section: Introductionmentioning

confidence: 99%