采用溶胶-凝胶结合快速退火工艺在p^+-Si基片上制备了Sr Ti O_3薄膜,构建了Ag/Sr Ti O_3/p^+-Si结构的阻变器件,研究了退火温度对薄膜微观结构、阻变特性的影响。结果表明:不同退火温度下薄膜均呈结晶态,并且随退火温度升高,薄膜晶粒有...采用溶胶-凝胶结合快速退火工艺在p^+-Si基片上制备了Sr Ti O_3薄膜,构建了Ag/Sr Ti O_3/p^+-Si结构的阻变器件,研究了退火温度对薄膜微观结构、阻变特性的影响。结果表明:不同退火温度下薄膜均呈结晶态,并且随退火温度升高,薄膜晶粒有增大的趋势,当退火温度为750℃时,薄膜的衍射峰不明显并且有杂峰出现。不同退火温度下Ag/Sr Ti O_3/p^+-Si器件都具有明显的双极性阻变特性,但退火温度为850℃与900℃的器件在扫描电压达到某一值时电流会出现一个极小值;经850℃退火处理的器件具有更高的高低电阻比(103～104)。当退火温度为800℃及更高时,器件在高阻态下的导电机制以肖特基势垒发射机制为主;低阻态的电荷传导机制则遵循空间电荷限制电流机制(SCLC)。器件在200次可逆循环测试下,退火温度为850℃时表现出较好的抗疲劳特性。展开更多
The 0.6 mol% CuO-doping 0.996(0.95 Na_(0.5)K_(0.5)NbO_3-0.05 LiSbO_3)-0.004 FeBiO_3(KNN-LSBF-CuO) piezoelectric ceramics were synthesized by a solid-state reaction technique, and the structure and piezoelectric proper...The 0.6 mol% CuO-doping 0.996(0.95 Na_(0.5)K_(0.5)NbO_3-0.05 LiSbO_3)-0.004 FeBiO_3(KNN-LSBF-CuO) piezoelectric ceramics were synthesized by a solid-state reaction technique, and the structure and piezoelectric properties dependence of sintering time in KNN-LS-BF-CuO ceramics were studied. It is found that all the samples sintered for various time are perovskite structure mixed with orthorhombic symmetry phase and tetragonal phase, but the sintering time has significant influences on the crystalline and properties. When the sintering time increases from 2 hours to 6 hours, the grain of KNN-LS-BF-CuO ceramics becomes more homogeneous and more tight-arrangement. The experimental results reveal that the longer sintering time than 4 hours is beneficial for improving partial properties, such as d_(33), tgδ, and Q_m, but is adverse to ε_r and k_p, the KNNLS-BF-CuO ceramics with optimum properties can be synthesized for 6 hours at 1 060 ℃.展开更多
The Ag/Mg0.2Zn0.8O/ZnMn2O4/p^＋-Si heterostructure devices were fabricated by sol-gel spin coating technique and the resistive switching behavior,conduction mechanism,endurance characteristic,and retention properties ...The Ag/Mg0.2Zn0.8O/ZnMn2O4/p^＋-Si heterostructure devices were fabricated by sol-gel spin coating technique and the resistive switching behavior,conduction mechanism,endurance characteristic,and retention properties were investigated.A distinct bipolar resistive switching behavior of the devices was observed at room temperature.The resistance ratio R_（HRS）/RLRS of high resistance state and low resistance state is as large as four orders of magnitude with a readout voltage of 2.0 V.The dominant conduction mechanism of the device is trap-controlled space charge limited current（SCLC）.The devices exhibit good durability under 1×10^3cycles and the degradation is invisible for more than 10^6 s.展开更多
ZnMn_2O_4 films for resistance random access memory（RRAM） were fabricated with different device structures by magnetron sputtering. The effects of electrode on I-V characteristics, resistance switching behavior, end...ZnMn_2O_4 films for resistance random access memory（RRAM） were fabricated with different device structures by magnetron sputtering. The effects of electrode on I-V characteristics, resistance switching behavior, endurance and retention characteristics of ZnMn_2O_4 films were investigated. The ZnMn_2O_4 films, using p-Si and Pt as bottom electrode, exhibit bipolar resistive switching（BRS） behavior dominated by the space-charge-limited conduction（SCLC） mechanism in the high resistance state（HRS） and the filament conduction mechanism in the low resistance state（LRS）, but the ZnMn_2O_4 films using n-Si as bottom electrodes exhibit both bipolar and unipolar resistive switching behaviors controlled by the Poole-Frenkel（P-F） conduction mechanism in both HRS and LRS. Ag/ZnMn_2O_4/p-Si device possesses the best endurance and retention characteristics, in which the number of stable repetition switching cycle is over 1000 and the retention time is longer than 106 seconds. However, the highest RHRS/R_（LRS） ratio of 104 and the lowest V_（ON） and V_（OFF） of 3.0 V have been observed in Ag/ZnMn_2O_4/Pt device. Though the Ag/ZnMn_2O_4/n-Si device also possesses the highest RHRS/R_（LRS） ratio of 104, but the highest values of V_（ON）,V_（OFF）, RHRS and R_（LRS）, as well as the poor endurance and retention characteristics.展开更多
A resistance random access memory（RRAM） with a structure of Ag/ZnMn2O4/p-Si was fabricated by magnetron sputtering method. Reliable and repeated switching of the resistance of ZnMn2O4 fi lms was obtained between two...A resistance random access memory（RRAM） with a structure of Ag/ZnMn2O4/p-Si was fabricated by magnetron sputtering method. Reliable and repeated switching of the resistance of ZnMn2O4 fi lms was obtained between two well-defi ned states of high and low resistance with a narrow dispersion and 3V switching voltages. Resistance ratio of the high resistance state and low resistance state was found in the range of around 10^3 orders of magnitude and up to about 10^3 test cycles. The retention time of Ag/ZnMn2O4/p-Si device is longer than 10^6 seconds and the resistance ratio between two states remains higher than 10^3 at room temperature, showing a remarkable reliability performance of the RRAM devices for nonvolatile memory application. The equivalent simulation circuits for HRS（high resistance state） and LRS（low resistance state） were also studied by impedance spectroscopy.展开更多
SrTi1-yMgyO3 films were synthesized through sol-gel method on p^+-Si substrates. The effects of Mg doping concentration on the microstructure, switching behavior and properties of SrTi1-yMgyO3 films were investigated....SrTi1-yMgyO3 films were synthesized through sol-gel method on p^+-Si substrates. The effects of Mg doping concentration on the microstructure, switching behavior and properties of SrTi1-yMgyO3 films were investigated. All SrTi1-yMgyO3 films are polycrystalline, but the grain becomes coarser, and the number of holes is reduced when the Mg doping content increases from 0.04 to 0.16. SrTi1-yMgyO3 films with different Mg doping concentrations all show bipolar resistive switching behaviors but display some differences in switching properties. When y=0.08, the SrTi1-yMgyO3 films show the largest RHRS/RLRS of 105 and better fatigue endurance after 103 cycles. When y≥0.08, the distribution of Vset and Vreset is narrow, indicating good stability of writing and erasing data for a resistive random access memory. At high-resistance state, the dominant conduction mechanism of SrTi1-yMgyO3 films is the Schottky emission mechanism. However, at low-resistance state, the dominant conduction mechanisms are the filamentary conduction and changes to space charge limited current when y=0.16.展开更多
Ag/La0.5Mgo 5MnO3/p+-Si resistance switching device for nonvolatile memory application was fabricated by sol-gel method. The thickness effects of La0 5Mgo 5MnO3 (LMMO) films on current-voltage (I-V) characteristics, r...Ag/La0.5Mgo 5MnO3/p+-Si resistance switching device for nonvolatile memory application was fabricated by sol-gel method. The thickness effects of La0 5Mgo 5MnO3 (LMMO) films on current-voltage (I-V) characteristics, resistance switching behaviour and endurance characteristics of Ag/LMMO/p+-Si device were investigated. The same crystallisation and phase structure were confirmed in the LMMO films with increased film thickness. The Ag/LMMO/p+-Si device exhibits the typical bipolar resistive switching behaviour. As the LMMO thickness and the stable repetition switching cycle numbers increase, and KRescl of the device will increase, but the /^hrs^lrs will decrease. The Ag/LMMO/p+-Si device with 165 nm thick LMMO films exhibit the best performance, in which the RHRS/RLRS exceeds 104 for 1 000 switching cycles, and its degradation is invisible for more than 106 s.展开更多
Ho doping 0.825K_(0.5)Na_(0.5)NbO_(3)-0.175Sr(Yb_(0.5)Nb_(0.5))_(O3)(KNN-SYbN-x%Ho)transparent ceramics were prepared by solid-state sintering method.The structure,ferroelectric,energy storage,and optical properties o...Ho doping 0.825K_(0.5)Na_(0.5)NbO_(3)-0.175Sr(Yb_(0.5)Nb_(0.5))_(O3)(KNN-SYbN-x%Ho)transparent ceramics were prepared by solid-state sintering method.The structure,ferroelectric,energy storage,and optical properties of KNN-SYbN-x%Ho were explored.With the addition of Ho,under the excitation of a 980 nm laser,the ceramics exhibit up-conversion luminescence properties with wavelengths of 550 nm and 670 nm,however,the ceramics change from pseudo-cubic phase to triphase-orthorhombic phase and the light transmittance decreases.The addition of Ho significantly enhances the ferroelectric properties and the energy storage performance of KNN-SYbN-x%Ho ceramics.When x=0.15,the residual polarization P_(r)=9.11μC/cm^(2),while x=0.20,the maximum energy storage density W_(rec) reaches 0.26 J/cm^(3),and the energy storage efficiencyηreaches 87.1%.展开更多
文摘采用溶胶-凝胶结合快速退火工艺在p^+-Si基片上制备了Sr Ti O_3薄膜,构建了Ag/Sr Ti O_3/p^+-Si结构的阻变器件,研究了退火温度对薄膜微观结构、阻变特性的影响。结果表明:不同退火温度下薄膜均呈结晶态,并且随退火温度升高,薄膜晶粒有增大的趋势,当退火温度为750℃时,薄膜的衍射峰不明显并且有杂峰出现。不同退火温度下Ag/Sr Ti O_3/p^+-Si器件都具有明显的双极性阻变特性,但退火温度为850℃与900℃的器件在扫描电压达到某一值时电流会出现一个极小值;经850℃退火处理的器件具有更高的高低电阻比(103～104)。当退火温度为800℃及更高时,器件在高阻态下的导电机制以肖特基势垒发射机制为主;低阻态的电荷传导机制则遵循空间电荷限制电流机制(SCLC)。器件在200次可逆循环测试下,退火温度为850℃时表现出较好的抗疲劳特性。
基金Funded by the Guangxi Natural Science Foundation(No.2010GXNSFD013007)
文摘The 0.6 mol% CuO-doping 0.996(0.95 Na_(0.5)K_(0.5)NbO_3-0.05 LiSbO_3)-0.004 FeBiO_3(KNN-LSBF-CuO) piezoelectric ceramics were synthesized by a solid-state reaction technique, and the structure and piezoelectric properties dependence of sintering time in KNN-LS-BF-CuO ceramics were studied. It is found that all the samples sintered for various time are perovskite structure mixed with orthorhombic symmetry phase and tetragonal phase, but the sintering time has significant influences on the crystalline and properties. When the sintering time increases from 2 hours to 6 hours, the grain of KNN-LS-BF-CuO ceramics becomes more homogeneous and more tight-arrangement. The experimental results reveal that the longer sintering time than 4 hours is beneficial for improving partial properties, such as d_(33), tgδ, and Q_m, but is adverse to ε_r and k_p, the KNNLS-BF-CuO ceramics with optimum properties can be synthesized for 6 hours at 1 060 ℃.
基金Funded by the National Natural Science Foundation of China(No.51262003)the Guangxi Key Laboratory of Information Materials(Guilin University of Electronic Technology),China(No.1110908-10-Z)
文摘The Ag/Mg0.2Zn0.8O/ZnMn2O4/p^＋-Si heterostructure devices were fabricated by sol-gel spin coating technique and the resistive switching behavior,conduction mechanism,endurance characteristic,and retention properties were investigated.A distinct bipolar resistive switching behavior of the devices was observed at room temperature.The resistance ratio R_（HRS）/RLRS of high resistance state and low resistance state is as large as four orders of magnitude with a readout voltage of 2.0 V.The dominant conduction mechanism of the device is trap-controlled space charge limited current（SCLC）.The devices exhibit good durability under 1×10^3cycles and the degradation is invisible for more than 10^6 s.
基金Funded by the National Natural Science Foundation of China(51262003)the Guangxi Key Laboratory of Information Materials(Guilin University of Electronic Technology),China(No.1110908-10-Z)
文摘ZnMn_2O_4 films for resistance random access memory（RRAM） were fabricated with different device structures by magnetron sputtering. The effects of electrode on I-V characteristics, resistance switching behavior, endurance and retention characteristics of ZnMn_2O_4 films were investigated. The ZnMn_2O_4 films, using p-Si and Pt as bottom electrode, exhibit bipolar resistive switching（BRS） behavior dominated by the space-charge-limited conduction（SCLC） mechanism in the high resistance state（HRS） and the filament conduction mechanism in the low resistance state（LRS）, but the ZnMn_2O_4 films using n-Si as bottom electrodes exhibit both bipolar and unipolar resistive switching behaviors controlled by the Poole-Frenkel（P-F） conduction mechanism in both HRS and LRS. Ag/ZnMn_2O_4/p-Si device possesses the best endurance and retention characteristics, in which the number of stable repetition switching cycle is over 1000 and the retention time is longer than 106 seconds. However, the highest RHRS/R_（LRS） ratio of 104 and the lowest V_（ON） and V_（OFF） of 3.0 V have been observed in Ag/ZnMn_2O_4/Pt device. Though the Ag/ZnMn_2O_4/n-Si device also possesses the highest RHRS/R_（LRS） ratio of 104, but the highest values of V_（ON）,V_（OFF）, RHRS and R_（LRS）, as well as the poor endurance and retention characteristics.
基金Funded by the National Natural Science Foundation of China(51262003)the Guangxi Key Laboratory of Information Materials(Guilin University of Electronic Technology),China(No.1110908-10-Z)
文摘A resistance random access memory（RRAM） with a structure of Ag/ZnMn2O4/p-Si was fabricated by magnetron sputtering method. Reliable and repeated switching of the resistance of ZnMn2O4 fi lms was obtained between two well-defi ned states of high and low resistance with a narrow dispersion and 3V switching voltages. Resistance ratio of the high resistance state and low resistance state was found in the range of around 10^3 orders of magnitude and up to about 10^3 test cycles. The retention time of Ag/ZnMn2O4/p-Si device is longer than 10^6 seconds and the resistance ratio between two states remains higher than 10^3 at room temperature, showing a remarkable reliability performance of the RRAM devices for nonvolatile memory application. The equivalent simulation circuits for HRS（high resistance state） and LRS（low resistance state） were also studied by impedance spectroscopy.
基金Funded by the Guangxi Natural Science Foundation(2015GXNSFAA139253)
文摘SrTi1-yMgyO3 films were synthesized through sol-gel method on p^+-Si substrates. The effects of Mg doping concentration on the microstructure, switching behavior and properties of SrTi1-yMgyO3 films were investigated. All SrTi1-yMgyO3 films are polycrystalline, but the grain becomes coarser, and the number of holes is reduced when the Mg doping content increases from 0.04 to 0.16. SrTi1-yMgyO3 films with different Mg doping concentrations all show bipolar resistive switching behaviors but display some differences in switching properties. When y=0.08, the SrTi1-yMgyO3 films show the largest RHRS/RLRS of 105 and better fatigue endurance after 103 cycles. When y≥0.08, the distribution of Vset and Vreset is narrow, indicating good stability of writing and erasing data for a resistive random access memory. At high-resistance state, the dominant conduction mechanism of SrTi1-yMgyO3 films is the Schottky emission mechanism. However, at low-resistance state, the dominant conduction mechanisms are the filamentary conduction and changes to space charge limited current when y=0.16.
基金Funded by the National Natural Science Foundation of China(No.51262003)the Guangxi Natural Science Foundation(No.2015GXNSFAA139253)
文摘Ag/La0.5Mgo 5MnO3/p+-Si resistance switching device for nonvolatile memory application was fabricated by sol-gel method. The thickness effects of La0 5Mgo 5MnO3 (LMMO) films on current-voltage (I-V) characteristics, resistance switching behaviour and endurance characteristics of Ag/LMMO/p+-Si device were investigated. The same crystallisation and phase structure were confirmed in the LMMO films with increased film thickness. The Ag/LMMO/p+-Si device exhibits the typical bipolar resistive switching behaviour. As the LMMO thickness and the stable repetition switching cycle numbers increase, and KRescl of the device will increase, but the /^hrs^lrs will decrease. The Ag/LMMO/p+-Si device with 165 nm thick LMMO films exhibit the best performance, in which the RHRS/RLRS exceeds 104 for 1 000 switching cycles, and its degradation is invisible for more than 106 s.
基金Funded by the National Nature Science Foundation of China(No.61965007)the Guangxi Nature Science Foundation,China(No.2018GXNSFDA281042)the Guangxi Key Laboratory of Information Materials(Guilin University of Electronic Technology),China(No.201007-Z)。
文摘Ho doping 0.825K_(0.5)Na_(0.5)NbO_(3)-0.175Sr(Yb_(0.5)Nb_(0.5))_(O3)(KNN-SYbN-x%Ho)transparent ceramics were prepared by solid-state sintering method.The structure,ferroelectric,energy storage,and optical properties of KNN-SYbN-x%Ho were explored.With the addition of Ho,under the excitation of a 980 nm laser,the ceramics exhibit up-conversion luminescence properties with wavelengths of 550 nm and 670 nm,however,the ceramics change from pseudo-cubic phase to triphase-orthorhombic phase and the light transmittance decreases.The addition of Ho significantly enhances the ferroelectric properties and the energy storage performance of KNN-SYbN-x%Ho ceramics.When x=0.15,the residual polarization P_(r)=9.11μC/cm^(2),while x=0.20,the maximum energy storage density W_(rec) reaches 0.26 J/cm^(3),and the energy storage efficiencyηreaches 87.1%.
