A Molecular Ferroelectric Showing Room-Temperature Record-Fast Switching of Spontaneous Polarization

2018 ◽  
Vol 130 (31) ◽  
pp. 9981-9985 ◽  
Author(s):  
Zhihua Sun ◽  
Xianfeng Yi ◽  
Kewen Tao ◽  
Chengmin Ji ◽  
Xitao Liu ◽  
...  
Keyword(s):  
Spontaneous Polarization ◽  
Room Temperature ◽  
Temperature Record ◽  
Fast Switching

A Molecular Ferroelectric Showing Room-Temperature Record-Fast Switching of Spontaneous Polarization

2018 ◽  
Vol 57 (31) ◽  
pp. 9833-9837 ◽  
Author(s):  
Zhihua Sun ◽  
Xianfeng Yi ◽  
Kewen Tao ◽  
Chengmin Ji ◽  
Xitao Liu ◽  
...  
Keyword(s):  
Spontaneous Polarization ◽  
Room Temperature ◽  
Temperature Record ◽  
Fast Switching

Study on Fabrication and Fast Switching of High Voltage SiC JFET

2013 ◽  
Vol 827 ◽  
pp. 282-286
Author(s):  
Gang Chen ◽  
Song Bai ◽  
Run Hua Huang ◽  
Yong Hong Tao ◽  
Ao Liu
Keyword(s):  
Gate Voltage ◽  
Room Temperature ◽  
Inversion Layer ◽  
Oxide Semiconductor ◽  
Low Loss ◽  
Semiconductor Interface ◽  
Fast Switching ◽  
High Temperature Operation ◽  
Off Time ◽  
Channel Region

SiC devices have excellent properties such as ultra low loss, high withstand voltage, large capacity, high frequency, and high temperature operation compared with Si devices. The SiC JFET is expected to be appropriate for the power device because a JFET has no oxide-semiconductor interface in the channel region and does not use the low mobility SiC MOSFET inversion layer as a channel. Forward I-V up to 4A for SiC VJFET, Gate voltage from 2V to 3.5V by step 0.5V. Reverse I-V characteristics up to 4500V (VG=-8V) for SiC VJFET, Gate voltage from-4V to-8V by step-2V. Turn-off characteristics are studied and fast turn-off time of 136ns at room temperature under DC voltage of 600V is successfully demonstrated.

EFFECT OF YTTRIUM ON DIELECTRIC, PYROELECTRIC AND PIEZOELECTRIC PROPERTIES OF PBN FERROELECTRICS

2006 ◽  
Vol 20 (21) ◽  
pp. 3081-3091 ◽  
Author(s):  
K. SAMBASIVA RAO ◽  
N. VALLIS NATH ◽  
P. MURALI KRISHNA ◽  
D. MADHAVA PRASAD ◽  
JOON HYUNG LEE
Keyword(s):  
Transition Temperature ◽  
Spontaneous Polarization ◽  
Room Temperature ◽  
Piezoelectric Properties ◽  
Pyroelectric Coefficient ◽  
Tetragonal Symmetry ◽  
Maximum Volume ◽  
Stiffness Constant ◽  
Method Substitution ◽  
Sintering Method

Materials with batch formula Pb (1-x-3y/2) R y Ba x Nb 2 O 6, where R=Y, (1-x)=0.73, 0.63, 0.53 and y=0.00, 0.02 have been prepared by the double sintering method. Substitution of yttrium (Y) restored tetragonal symmetry of PBN but reduced lattice parameters, cell volume and enhanced the density. Transition temperature of PBN has decreased due to the substitution of Y3+. Enhanced room temperature spontaneous polarization (Ps)=149.97 μ C/sq. cm has been observed in PBN53, which is above MPB, whereas enhanced value of Ps=112.74 μ C/sq. cm is found in Y: PBN63 at MPB region. The room temperature Pyroelectric coefficient (PRT=1.07) has been observed in the composition where maximum volume of Ps is obtained. Similarly, enhanced values of piezoelectric coefficients Kp=0.244, Kt=0.353, K31=0.131, d31=60, d33=159 and g31=3.65 have also been found in the same material PBN53. Substitution of Yttrium enhanced the stiffness constant 13.59 in PBN 73 to 14.27 of Y: PBN73.

Room Temperature Ferroelectric Terpolymers with Large Spontaneous Polarization

1995 ◽  
Vol 28 (15) ◽  
pp. 5274-5279 ◽  
Author(s):  
J. Naciri ◽  
B. R. Ratna ◽  
S. Baral-Tosh ◽  
P. Keller ◽  
R. Shashidhar
Keyword(s):  
Spontaneous Polarization ◽  
Room Temperature

2.2 kV SiC BJTs with Low VCESAT Fast Switching and Short-Circuit Capability

2010 ◽  
Vol 645-648 ◽  
pp. 1033-1036 ◽  
Author(s):  
Martin Domeij ◽  
Carina Zaring ◽  
Andrei O. Konstantinov ◽  
Muhammad Nawaz ◽  
Jan Olov Svedberg ◽  
...  
Keyword(s):  
Breakdown Voltage ◽  
Room Temperature ◽  
Short Circuit ◽  
Device Simulation ◽  
Active Area ◽  
Large Area ◽  
Fast Switching ◽  
Large Active Area ◽  
High Dynamic ◽  
Good Agreement

This paper reports large active area (15 mm2) 4H-SiC BJTs with a low VCESAT=0.6 V at IC=20 A (JC=133 A/cm2) and an open-base breakdown voltage BVCEO=2.3 kV at T=25 °C. The corresponding room temperature specific on-resistance RSP-ON=4.5 mΩcm2 is to the authors knowledge the lowest reported value for a large area SiC BJT blocking more than 2 kV. The on-state and blocking characteristics were analyzed by device simulation and found to be in good agreement with measurements. Fast switching with VCE rise- and fall-times in the range of 20-30 ns was demonstrated for a 6 A 1200 V rated SiC BJT. It was concluded that high dynamic base currents are essential for fast switching to charge the BJT parasitic base-collector capacitance. In addition, 10 μs short-circuit capability with VCE=800 V was shown for the 1200 V BJT.

Large Spontaneous Polarization and Clear Hysteresis Loop of a Room-Temperature Hybrid Ferroelectric Based on Mixed-Halide [BiI3Cl2] Polar Chains and Methylviologen Dication

2011 ◽  
Vol 133 (38) ◽  
pp. 14924-14927 ◽  
Author(s):  
Nicolas Leblanc ◽  
Nicolas Mercier ◽  
Leokadiya Zorina ◽  
Sergey Simonov ◽  
Pascale Auban-Senzier ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Spontaneous Polarization ◽  
Room Temperature

Electrooptic study of antiferroelectric mixtures for display application

2006 ◽  
Vol 14 (4) ◽  
Author(s):  
A. Mikułko ◽  
M. Marzec ◽  
S. Wróbel ◽  
R. Dąbrowski
Keyword(s):  
Field Theory ◽  
Phase Transitions ◽  
Electric Field ◽  
Tilt Angle ◽  
Spontaneous Polarization ◽  
Room Temperature ◽  
Mean Field Theory ◽  
Mean Field ◽  
Current Method ◽  
Range Measurements

AbstractThe aim of this paper is to study the influence of electric field on alignment of para-, ferro- and antiferroelectric phases in the vicinity of SmA* — SmC* or SmC* — SmCA* phase transitions as to obtain mono-domain cells. Four mixtures studied (W-193B, W-193B-1, W-201, W-204D) show the SmCA* phase in a wide room temperature range. Measurements of the spontaneous polarization versus temperature by using reversal current method give an answer to the question, what kind of the transitions take place between para-, ferro- or antiferroelectric phases using the Landau mean field theory. Optimal electrooptic parameters for different compositions of the mixtures such as tilt angle, spontaneous polarization and saturation voltage have been measured to compare parameters of the mixtures studied.

9 kV 4H-SiC IGBTs with 88 mΩ·cm2 of R diff, on

2007 ◽  
Vol 556-557 ◽  
pp. 771-774 ◽  
Author(s):  
Qing Chun Jon Zhang ◽  
Charlotte Jonas ◽  
Bradley Heath ◽  
Mrinal K. Das ◽  
Sei Hyung Ryu ◽  
...  
Keyword(s):  
High Temperature ◽  
Threshold Voltage ◽  
High Power ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Gate Bias ◽  
Channel Mobility ◽  
Fast Switching ◽  
Blocking Voltage ◽  
First Time

SiC IGBTs are suitable for high power, high temperature applications. For the first time, the design and fabrication of 9 kV planar p-IGBTs on 4H-SiC are reported in this paper. A differential on-resistance of ~ 88 m(cm2 at a gate bias of –20 V is achieved at 25°C, and decreases to ~24.8 m(cm2 at 200°C. The device exhibits a blocking voltage of 9 kV with a leakage current density of 0.1 mA/cm2. The hole channel mobility is 6.5 cm2/V-s at room temperature with a threshold voltage of –6.5 V resulting in enhanced conduction capability. Inductive switching tests have shown that IGBTs feature fast switching capability at both room and elevated temperatures.

Design, Yield and Process Capability Study of 8 kV 4H-SiC PIN Diodes

2012 ◽  
Vol 717-720 ◽  
pp. 953-956 ◽  
Author(s):  
Alex V. Bolotnikov ◽  
Peter A. Losee ◽  
Kevin Matocha ◽  
Jeff Nasadoski ◽  
John Glaser ◽  
...  
Keyword(s):  
Material Properties ◽  
Room Temperature ◽  
Voltage Drop ◽  
Quality Improvements ◽  
Forward Voltage ◽  
Pin Diodes ◽  
Size Dependent ◽  
Fast Switching ◽  
Forward Voltage Drop ◽  
Design Yield

This paper presents a study of performance and scalability of 8kV SiC PIN diodes focusing on area-dependent yield and sensitivity to material properties variation. Successfully fabricated 18 and 36 mm2 SiC-PiN diodes exhibited avalanche breakdown above 8 kV and < 5V forward voltage drop at 100 A/cm2 current density. The fast switching operation of these diodes up to ~5 kHz frequency is evidenced by reverse recovery measurements with by double-pulse inductive switching tests. The devices exhibit 0.142 and 0.169 uC/cm2 stored charge at room temperature and 125oC, respectively, when turned-off from Jf = 100A/cm2 to Vr = 2.1 kV. The measured diode breakdown voltage exhibited location and size dependent yield, indicating the necessity of material quality improvements for production.

Induction of a room temperature ferroelectric SmC* phase in binary mixtures with moderate spontaneous polarization and sub-millisecond switching time

RSC Advances ◽  
2016 ◽  
Vol 6 (87) ◽  
pp. 84369-84378 ◽  
Author(s):  
A. Debnath ◽  
P. K. Mandal ◽  
D. Węglowska ◽  
R. Dąbrowski
Keyword(s):  
Binary Mixture ◽  
Binary Mixtures ◽  
Spontaneous Polarization ◽  
Room Temperature ◽  
Switching Time

Induction of room temperature SmC* phase in binary mixture.

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