Improved varistor nonlinearity via sintering and acceptor impurity doping

Wang, Y. J.; Wang, J. F.; Li, C. P.; Chen, H. C.; Su, Weizhou; Zhong, Wenhui; Zhang, P. L.; Zhao, Lei

doi:10.1051/epjap:2000157

Cited by 34 publications

(9 citation statements)

References 22 publications

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“…They found that SnO 2 -based ceramics doped with 1.00 mol% CoO and 0.05 mol% Nb 2 O 5 were a promising varistor material. [5][6][7][8][9] Wang et al 10,11 found that (Bi, Nb)-doped SnO 2 -and (Zn, Nb)-doped SnO 2 also exhibit varistor nonlinearity.…”

Section: Introductionmentioning

confidence: 99%

(Pr, Co, Nb)‐Doped SnO₂ Varistor Ceramics

Wang

Chen

et al. 2005

Journal of the American Ceramic Society

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The effect on microstructure and electrical properties of (Co, Nb)‐doped SnO2 varistors upon the addition of Pr2O3 was investigated by scanning electron microscopy and by determining I–V, ɛ–f, and R–f relations. The threshold electric field of the SnO2‐based varistors increased significantly from 850 to 2280 V/mm, and the relative dielectric constants of the SnO2‐based varistors decreased greatly from 784 to 280 as Pr2O3 concentration was increased up to 0.3 mol%. The significant decrease of the SnO2 grain size, from 4.50 to 1.76 μm with increasing Pr2O3 concentration over the range of 0–0.3 mol%, is the origin for the increase in the threshold voltage and decrease of the dielectric constants. The grain size reduction is attributed to the segregation of Pr2O3 at grain boundaries hindering the SnO2 grains from conglomerating into large particles. Varistors were found to have a superhigh threshold voltage and a comparatively large nonlinear coefficient α. For 0.15 mol% Pr2O3‐doped sample, threshold electric field and nonlinear coefficient α were measured to be 1540 V/mm and 61, and for 0.3 mol% Pr2O3‐doped sample, V and α were 2150 V/mm and 42, respectively. Superhigh threshold voltage and large nonlinear coefficient α qualify the Pr‐doped SnO2 varistor as an excellent candidate for a high voltage protection system.

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Section: Introductionmentioning

confidence: 99%

(Pr, Co, Nb)‐Doped SnO₂ Varistor Ceramics

Wang

Chen

et al. 2005

Journal of the American Ceramic Society

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“…In a system of SnO 2 -Bi 2 O 3 -Nb 2 O 5 α ¼ 14 and E 1 ¼ 19; 500 V cm À 1 were obtained [11]. The role of the Bi 2 O 3 addition in reaching of a high nonlinearity coefficient is considered rather as insignificant [10,11]. However, in the SnO 2 -Bi 2 O 3 -Co 3 O 4 -Nb 2 O 5 -Cr 2 O 3 system with quite large amounts of Nb 2 O 5 and Cr2O3 (0.5 mol%) the nonlinearity coefficient reaches 55-60 in the electric fields of about 3500 V cm À 1 [12].…”

Section: Introductionmentioning

confidence: 98%

“…The same system was studied later [10]. In a system of SnO 2 -Bi 2 O 3 -Nb 2 O 5 α ¼ 14 and E 1 ¼ 19; 500 V cm À 1 were obtained [11]. The role of the Bi 2 O 3 addition in reaching of a high nonlinearity coefficient is considered rather as insignificant [10,11].…”

Section: Introductionmentioning

confidence: 99%

Electrical properties of SnO2 ceramics for low voltage varistors

Glot

Bulpett

Ivon

et al. 2015

Physica B: Condensed Matter

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“…22,23 Actually, the method of acceptor impurity doping has been proven to be effective in reducing oxygen vacancies in heteroepitaxial films. 24,25 However, as a result of inappropriate growth scheme designs, most of the reported acceptor impurities doped Ga 2 O 3 films present polycrystalline, mixed crystal, and amorphous structures. 26−29 Compared with single crystal orientation Ga 2 O 3 films, those films exhibit more grain boundaries, which lead to an increased probability of carriers being trapped or scattered.…”

Section: ■ Introductionmentioning

confidence: 99%

“…β-Ga 2 O 3 , an intrinsic n-type semiconductor with an ultrawide bandgap (∼4.9 eV), is considered to be an ideal candidate for preparing SBUV PDs. , During the growth of β-Ga 2 O 3 , the easily formed oxygen vacancies are usually considered as the cause for the n-type characteristics of β-Ga 2 O 3 . , However, oxygen vacancies are prone to form photoacoustic carrier trapping centers; thus, most of the previously reported Ga 2 O 3 -based PDs exhibit slow response speed and low photoresponsivity. , Actually, the method of acceptor impurity doping has been proven to be effective in reducing oxygen vacancies in heteroepitaxial films. , However, as a result of inappropriate growth scheme designs, most of the reported acceptor impurities doped Ga 2 O 3 films present polycrystalline, mixed crystal, and amorphous structures. − Compared with single crystal orientation Ga 2 O 3 films, those films exhibit more grain boundaries, which lead to an increased probability of carriers being trapped or scattered. ,− Therefore, the photoresponsivity of the PDs based on these films is relatively low. − , …”

Section: Introductionmentioning

confidence: 99%

High-Performance Solar Blind Ultraviolet Photodetector Based on Single Crystal Orientation Mg-Alloyed Ga₂O₃ Film Grown by a Nonequilibrium MOCVD Scheme

Zhang

et al. 2019

ACS Appl. Electron. Mater.

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It is crucial to realize high photoresponsivity and a fast response speed to meet the application requirements of solar blind ultraviolet (SBUV) photodetectors (PDs) in wireless communication, fire warning, and other fields. Such high-performance PDs depend on high-quality films. In this paper, a nonequilibrium MOCVD growth scheme is reported to obtain Mg-alloyed Ga2O3 films with single crystal orientation. On the basis of this film, the fabricated PD exhibits a large on/off ratio of approximately 105 (I 254 nm light/I dark), ultrahigh external quantum efficiency of 4341%, and high photoresponsivity of 8.9 A/W under 3 V bias. The performance of this device is greatly enhanced compared to the performances of those PDs based on amorphous gallium oxide films previously reported, which is attributed to the fewer number of grain boundaries of the single crystal orientation Ga2O3 films. Furthermore, it is found that under the same growth conditions, Ga2O3 films doped with an appropriate amount of acceptor impurity Mg possess less oxygen vacancies and better crystal quality, compared with unalloyed Ga2O3 films. The characterizations indicate that the Mg-alloyed Ga2O3 films with single crystal orientation grown by the nonequilibrium MOCVD scheme are feasible for preparing high-performance SBUV PDs.

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Improved varistor nonlinearity via sintering and acceptor impurity doping

Cited by 34 publications

References 22 publications

(Pr, Co, Nb)‐Doped SnO₂ Varistor Ceramics

(Pr, Co, Nb)‐Doped SnO₂ Varistor Ceramics

Electrical properties of SnO2 ceramics for low voltage varistors

High-Performance Solar Blind Ultraviolet Photodetector Based on Single Crystal Orientation Mg-Alloyed Ga₂O₃ Film Grown by a Nonequilibrium MOCVD Scheme

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Improved varistor nonlinearity via sintering and acceptor impurity doping

Cited by 34 publications

References 22 publications

(Pr, Co, Nb)‐Doped SnO2 Varistor Ceramics

(Pr, Co, Nb)‐Doped SnO2 Varistor Ceramics

Electrical properties of SnO2 ceramics for low voltage varistors

High-Performance Solar Blind Ultraviolet Photodetector Based on Single Crystal Orientation Mg-Alloyed Ga2O3 Film Grown by a Nonequilibrium MOCVD Scheme

Contact Info

Product

Resources

About

(Pr, Co, Nb)‐Doped SnO₂ Varistor Ceramics

(Pr, Co, Nb)‐Doped SnO₂ Varistor Ceramics

High-Performance Solar Blind Ultraviolet Photodetector Based on Single Crystal Orientation Mg-Alloyed Ga₂O₃ Film Grown by a Nonequilibrium MOCVD Scheme