利用新型铁电材料Na 0.5 Y 0.5 TiO 3(NYTO)薄膜高介电的特点,将其作为MFIS(metal-ferroelectric-insulator-semiconductor,MFIS)电容器的绝缘层,制备出Pt/Pb(Zr 0.2 Ti 0.8)O 3/NYTO/Si结构电容器,并对其进行XRD、SEM、C-V特性测试及I-...利用新型铁电材料Na 0.5 Y 0.5 TiO 3(NYTO)薄膜高介电的特点,将其作为MFIS(metal-ferroelectric-insulator-semiconductor,MFIS)电容器的绝缘层,制备出Pt/Pb(Zr 0.2 Ti 0.8)O 3/NYTO/Si结构电容器,并对其进行XRD、SEM、C-V特性测试及I-V特性测试分析.分别对C-V存储窗口(记忆窗口,memory window)与应用电压以及绝缘层膜厚的关系进行了研究,结果表明记忆窗口数值比较理想.绝缘层厚度为40 nm、电容器的应用电压为32 V时,记忆窗口可达13 V.对制备的MFIS电容器I-V特性进行了研究,结果表明器件具备较低的漏电流密度,为1.08×10-6 A/cm 2,且其电流传导机制符合空间电荷限制电流导电机制.展开更多
Metal-ferroelectric-insulator-silicon(MFIS) capacitors with Bi3.15Nd0.85Ti3O12(BNT) ferroelectric thin film were simulated using a commercial software Silvaco/Atlas,and the effects of applied voltage and insulator lay...Metal-ferroelectric-insulator-silicon(MFIS) capacitors with Bi3.15Nd0.85Ti3O12(BNT) ferroelectric thin film were simulated using a commercial software Silvaco/Atlas,and the effects of applied voltage and insulator layer on capacitance-voltage(C-V) hysteresis loops and memory windows were investigated. For the MFIS capacitors with CeO2 insulator,with the increase of applied voltage from 2 V to 15 V,the C-V loops become wider and memory windows increase from 0.15 V to 1.27 V. When the thickness of CeO2 layer increases from 1 nm to 5 nm at the applied voltage of 5 V,the C-V loops become narrower and the memory windows decrease from 1.09 V to 0.36 V. For MFIS capacitors with different insulator layers(CeO2,HfO2,Y2O3,Si3N4 and SiO2),the high dielectric constants can make the C-V loops wider and improve the capacitor's memory window. The simulation results prove that Silvaco/Atlas is a powerful simulator for MFIS capacitor,and they are helpful to the fabrication of MFIS nonvolatile memory devices.展开更多
The paper presents and examines the impact of corporate governance and ethics in particular on sustainable development of the Zimbabwean microfinance sector in the period 2009-2019.The critical microfinance institutio...The paper presents and examines the impact of corporate governance and ethics in particular on sustainable development of the Zimbabwean microfinance sector in the period 2009-2019.The critical microfinance institutions(MFIs)crisis experienced in Masvingo,Zimbabwe recently was not the first one in the world in terms of its severity.The main aim of MFIs in any economy is to serve the poor and vulnerable people of a society through providing them with soft or concessional loans,insurance coverage,and facilities for savings.The study used the descriptive qualitative design to draw research data from MFIs dotted in and around Masvingo Province for presentation,analysis,and interpretation.One of the major findings of the study was that corporate governance and ethics played an indispensable role in the growth and development of MFIs’products and services.The study also realized that good corporate governance and ethical behaviours in business practices were essential for the success of any organization and vice versa and MFIs were no exception.The study therefore concluded that poor capital formation,corporate governance and ethics,human recruitment and selection procedures and fraudulent activities or misappropriation of funds were responsible for the majority of threats faced by MFIs in Masvingo in their growth and development endeavours.Therefore the study recommended that directors of MFIs should craft policies and strategies that are corporate governance and ethics oriented in their desire to grow their business towards sustainable development in the foreseeable future.展开更多
基金Projects (10472099,0672139) supported by the National Natural Science Foundation of ChinaProject (207079) supported by Key Project of Ministry of Education of China+1 种基金Project (05FJ2005) supported by Key Project of Scientific and Technological Department of Hunan ProvinceProject(06A072) supported by Key Project of Education Department of Hunan Province
文摘Metal-ferroelectric-insulator-silicon(MFIS) capacitors with Bi3.15Nd0.85Ti3O12(BNT) ferroelectric thin film were simulated using a commercial software Silvaco/Atlas,and the effects of applied voltage and insulator layer on capacitance-voltage(C-V) hysteresis loops and memory windows were investigated. For the MFIS capacitors with CeO2 insulator,with the increase of applied voltage from 2 V to 15 V,the C-V loops become wider and memory windows increase from 0.15 V to 1.27 V. When the thickness of CeO2 layer increases from 1 nm to 5 nm at the applied voltage of 5 V,the C-V loops become narrower and the memory windows decrease from 1.09 V to 0.36 V. For MFIS capacitors with different insulator layers(CeO2,HfO2,Y2O3,Si3N4 and SiO2),the high dielectric constants can make the C-V loops wider and improve the capacitor's memory window. The simulation results prove that Silvaco/Atlas is a powerful simulator for MFIS capacitor,and they are helpful to the fabrication of MFIS nonvolatile memory devices.
文摘The paper presents and examines the impact of corporate governance and ethics in particular on sustainable development of the Zimbabwean microfinance sector in the period 2009-2019.The critical microfinance institutions(MFIs)crisis experienced in Masvingo,Zimbabwe recently was not the first one in the world in terms of its severity.The main aim of MFIs in any economy is to serve the poor and vulnerable people of a society through providing them with soft or concessional loans,insurance coverage,and facilities for savings.The study used the descriptive qualitative design to draw research data from MFIs dotted in and around Masvingo Province for presentation,analysis,and interpretation.One of the major findings of the study was that corporate governance and ethics played an indispensable role in the growth and development of MFIs’products and services.The study also realized that good corporate governance and ethical behaviours in business practices were essential for the success of any organization and vice versa and MFIs were no exception.The study therefore concluded that poor capital formation,corporate governance and ethics,human recruitment and selection procedures and fraudulent activities or misappropriation of funds were responsible for the majority of threats faced by MFIs in Masvingo in their growth and development endeavours.Therefore the study recommended that directors of MFIs should craft policies and strategies that are corporate governance and ethics oriented in their desire to grow their business towards sustainable development in the foreseeable future.
基金supported by the National Natural Science Foundation of China(62174059,51872099,and 91963102)Hong Kong Research Grant Council(15300619)+3 种基金Science and Technology Program of Guangzhou(201905-0001)Guangdong Science and Technology ProjectInternational Cooperation(2021A0505030064)the Program for Chang Jiang Scholars and Innovative Research Teams in Universities(IRT_17R40)the 111 Project。
