Transfer-free graphene passivation of sub 100 nm thin Pt and Pt–Cu electrodes for memristive devices

Memristive switches are among the most promising building blocks for future neuromorphic computing. These devices are based on a complex interplay of redox reactions on the nanoscale. Nanoionic phenomena enable non-linear and low-power resistance transition in ultra-short programming times. However, when not controlled, the same electrochemical reactions can result in device degradation and instability over time. Two-dimensional barriers have been suggested to precisely manipulate the nanoionic processes. But fabrication-friendly integration of these materials in memristive devices is challenging.Here we report on a novel process for graphene passivation of thin platinum and platinum/copper electrodes. We also studied the level of defects of graphene after deposition of selected oxides that are relevant for memristive switching

Hybrid 2D–CMOS microchips for memristive applications

Ministry of Science and Technology of China (grant nos. 2019YFE0124200 and 2018YFE0100800)National Natural Science Foundation of China (grant no. 61874075)Baseline funding scheme of the King Abdullah University of Science and Technolog

Investigation of Bipolar Resistive Switching Characteristics with Silicon Nitride device and bi-layer application by introducing the Al2O3 barrier layer

학위논문 (박사) -- 서울대학교 대학원 : 공과대학 재료공학부(하이브리드 재료), 2020. 8. 황철성.The resistance switching random access memory (ReRAM), which changes the resistance state of the device by the external electrical stimulation, is one of the promising candidates for a next-generation nonvolatile memory. Due to its simple metal-insulator-metal (MIM) structure, low power consumption, scalability, and complementary metal-oxide-semiconductor compatibility, ReRAM has been attracted enormous attention as a highly integrated memory to replace NAND flash memory. The transition metal oxides, such as NiO, TiO2, HfO2, and Ta2O5, were the main focus on the ReRAM device fabrication and mechanism analysis. On the other hand, the insulating nitride films, such as silicon nitride (Si3N4), have no reason for not being regarded as the feasible ReRAM material. In fact, the Si:N ratio of Si3N4 can be readily controlled to induce defects inside the film, which is already in massive use for charge-trap layer in NAND flash memory. The defect generation and possible percolation of the defects to form the so-called conducting filament (CF) is the main mechanism for the fluent ReRAM performance. Therefore, N-deficient Si3N4, i.e., Si3N4-x, can be a feasible resistance switching (RS) material. In the first part of this study, a bipolar resistive switching (BRS) property of a Si3N4-x thin film depending N-deficiency was investigated with Pt/Si3N4-x/TiN devices with various NH3 gas flow rate during plasma enhanced chemical vapor deposition process of Si3N4-x thin film. By X-ray photo-electron spectroscopy analysis, it was confirmed that the fraction of nitrogen element in Si3N4-x thin film decreased as NH3 gas flow rate decreased and the degree of N-deficiency could be controlled by changing NH3 gas flow rate. The change of N-deficiency affected the current-voltage (I-V) characteristics of Si3N4-x thin film, and the behavior of BRS and the optimized condition could be achieved. In addition, the series line resistance of Pt/TiN electrode was attributed to the self-compliance behavior, having a stable BRS behavior even without compliance current. The Si3N4-x devices didn't show cell area dependency of I-V characteristics, implying the formation and rupture of CF involved in the RS behavior. To further investigation of RS mechanism, the temperature dependent I-V behavior was examined. With a double logarithmic plot of the I-V curves, the slope of the best-linear-fitted data in the low and high voltage regions was ~1 and ~2, respectively, which coincide with the Childs law and space charge limited conduction mechanism dominated the conduction of Si3N4-x device. In addition, the activation energy and hopping distance for hopping conduction were calculated and both values decreased as NH3 gas flow rate decreased and after switching occured. From these results, CF is formed by the local repelling N to TiN BE and the percolation of the traps. The trap condition of the initial Si3N4-x played an important role in the formation of CF, otherwise the device underwent a hard breakdown. On the basis of the BRS property of a Si3N4-x thin film in the first part of this study, Al2O3 interfacial barrier layer (IBL) was inserted between the Si3N4-x thin film with optimized deposition condition (Si3N3.0) and Pt top electrode, forming the Pt/Al2O3/Si3N3.0/Ti devices with various Al2O3 film thickness (3-5 nm). The seperation between Al2O3 and Si3N3.0 layer could be identified with TEM image and EDS mapping image. While the Pt/Si3N3.0/Ti device showed filamentary BRS, the Pt/Al2O3/Si3N3.0/Ti devices showed electronic BRS with forming free property. In addition, the devices had self-rectifying and nonlinearity characteristics, which is necessary to prevent sneak current for big crossbar-array structure, due to the high band gap of Al2O3 IBL. The devices showed area dependency at HRS and LRS, indicating the interfacial electronic BRS dominated the RS mechanism. The temperature dependency analysis revealed the trap depth of trap sites in Si3N3.0 layer and schottky barreir height between Pt and Al2O3. Thus, the device switched its resistance state by trapping/detrapping of electrons at the trap sites in Si3N3.0 RS layer. To estimate the available maximum crossbar-array size (CBA), HSPICE simulation was performed and it was confirmed that ~106 density could be obtained. To form crossbar-array structure with ReRAM, sneak current is main issue for proper operation of selected cell. To suppress the sneak current, using transistor is a solution. However, relatively large size of transistor device hinders the scaling-down of ReRAM device. In this respect, selector device ,which has simple MIM sutucture, could replace a transistor while suppressing sneak current sufficiently. Therefore, it is needed to investigate the issue of integrated device with 1 selector and 1 RS material (1S1R). In the third part of this study, 1S1R device was fabricated with the Pt/Si3N4-x/TiN RS layer in the first part of this study and Pt/TiO2/TiN selector layer using the atomic-layer deposited TiO2 film. The device was fabricated via lift-off process with single cell, 2 by 2 and 9 by 9 crossbar-array pattern. By comparing each device, optimized deposition condition of selector and RS layer could be founded and additional issue to overcome was identified.외부 자극에 의해 소자의 저항상태를 변화시키는 저항 변화 메모리는 차세대 비휘발성 메모리의 유망한 후보 중 하나이다. 간단한 MIM 구조, 저전력 소모, 고 집적성 그리고 CMOS 적합성으로 인해 저항 변화 메모리는 NAND 플래시 메모리를 대체할 고집적 메모리로 많은 기대를 받고 있다. NiO, TiO2, HfO2 그리고Ta2O5와 같은 전이금속 산화물이 저항변화 메모리 소자 제작과 거동 분석의 주된 초점이였다. 반면에 Si3N4와 같은 질화막 또한 저항 변화 메모리로 쓰이지 않을 이유가 없을 것이다. 실제로 Si3N4의 Si와 N의 비율은 박막내의 결함을 유도하기위해 손쉽게 조절 가능하며, NAND 플래시 메모리에서의 charge trap layer로서도 이미 널리 쓰여지고 있다. 결함의 생성으로 인한 일명, 전도 필라멘트는 저항 변화 메모리의 주된 거동이다. 따라서 N 원소가 부족한 Si3N4 즉 Si3N4-x는 저항변화 물질로 사용 가능 할 것이다. 본 연구의 첫번째 파트에서는 N원소의 부족한 정도에 따른 Si3N4-x의 양극성 저항변화 특성 (BRS) 을 조사하기위해 Si3N4-x박막의 plasma enhanced chemical vapor deposition 과정 중에 사용되는 NH3가스 유량을 다양하게 하여 Pt/Si3N4-x/TiN 소자를 제작하였다. X-ray photo-electron spectroscopy 분석을 통해, NH3 가스 유량이 감소함에 따라 Si3N4-x 박막내의 질소 원소의 분율이 감소함을 확인할 수 있었고 NH3가스 유량을 조절함으로서 질소 원소의 부족한 정도를 조절할 수 있음을 알아내었다. 질소 원소의 부족한 정도는 Si3N4-x의 전류-전압 특성과 BRS 거동에 영향을 미치며 최적화된 조건을 찾을 수 있었다. 또한 Pt/TiN 전극의 직렬 선저항으로 인해 compliance 전류 없이 안정적인 BRS 거동을 보이는self-compliance 거동이 나타남을 확인하였다. Si3N4-x 소자는 전류-전압 특성에서 면적 의존성을 보이지 않았으며 이는 전도 필라멘트의 형성과 끊어짐에 의해 저항 변화 거동이 보임을 암시하였다. 저항 변화 거동의 추가적인 분석을 위해 전류-전압 특성의 온도의존성 측정을 진행하였다. 전류-전압 그래프의 더블 로그 플롯을 통해, 저전압과 고전압 영역대에서 피팅을 한 결과 1과 2가 각각 나옴을 확인하였으며 이는 childs law를 따르며 Si3N4-x의 전도가 space charge limited conduction에 의해 이루어짐을 알 수 있었다. 또한 hopping conduction을 위한 활성화 에너지와 hopping거리도 계산하였으며 두개의 값 모두 NH3가스 유량이 감소함에따라, 그리고 스위칭이 나타난 후에 감소함을 알 수 있었다. 이러한 결과로부터 질소 원소가 TiN 하부전극으로 밀려나가며 trap들이 뭉침으로 인해 전도 필라멘트가 형성됨을 확인할 수 있었다. 또한 초기 Si3N4-x의 trap 상태가 전도 필라멘트 형성에 중요한 역할을 하며 그렇지 않으면 소자는 망가지는 것을 확인하였다. 본 연구의 첫 번째 파트에서의 Si3N4-x 박막의 BRS 특성에 기초하여, Al2O3 계면 장벽 층이 최적화 된 증착 조건으로 만들어진 Si3N3.0층과 Pt 상부 전극 사이에 삽입되으며 그 결과 다양한 Al2O3 막 두께 (3-5 nm)를 갖는 Pt/Al2O3/Si3N3.0/Ti 소자를 형성 하였다. TEM 이미지와 EDS 매핑 이미지로 Al2O3와 Si3N3.0 층 사이의 분리를 확인 가능하였다. Pt/Si3N3.0/Ti 소자는 필라멘트의 BRS 특성을 나타내지만, Pt/Al2O3/Si3N3.0/Ti 소자는 forming-free특성을 갖는 e-BRS특성을 나타냈다. 또한 이 소자는 자체 정류 특성 및 비선형성 특성을 가지는데, 이러한 특성은 큰 사이즈의 크로스바 어레이 (CBA) 구조에서 누설전류를 방지하는데 도움이 되며, Al2O3층의 높은 밴드 갭으로 인해 이러한 특성이 나타나게 된다. 장치는 HRS 및 LRS에서 면적 의존성을 보여 주었으며 이는 계면의 e-BRS 저항 변화 메커니즘을 지배 한다는 것을 나타낸다. 또한 온도 의존성 분석을 통해 Si3N3.0 층에 존재하는 trap site의 trap 깊이 및 Pt와 Al2O3 사이의 쇼트키 배리어 높이를 알아낼 수 있었다. 따라서, 해당 소자는 Si3N3.0 저항 변화층의 trap site에서 전자를 트래핑 / 디트랩핑하여 저항 상태를 바꾼다는 걸 확인 가능하였다. 또한 가능한 최대 CBA 크기를 추정하기 위해 HSPICE 시뮬레이션을 수행하였으며 약 106 의 값을 얻을 수 있음을 확인하였다. 저항 변화 메모리로 CBA 구조를 형성할 때, 선택된 셀의 적절한 구동을 위해선 누설 전류가 가장 큰 문제이다. 누설 전류를 억제하기 위해, 트랜지스터의 사용은 하나의 해결책이 될 수 있다. 하지만, 상대적으로 큰 사이즈의 트랜지스터 소자는 저항 변화 메모리의 고집적을 방해하게 된다. 이러한 점에서 간단한 MIM구조를 갖는 선택소자는 누설전류를 충분히 억제하면서 트랜지스터를 대체할 수 있을것이다. 따라서 1 선택소자 1 저항변화 물질의 적층된 소자 (1S1R) 에서 생길 수 있는 문제점에 대해 조사할 필요가 있다. 본 연구의 세번째 파트에서는, 첫번째 파트에서의 Pt/Si3N4-x/TiN 저항 변화 소자와 ALD TiO2 박막을 사용한 Pt/TiO2/TiN 선택소자를 이용하여 1S1R소자를 제작하였다. 해당 소자는 lift-off 공정을 통해 단일소자, 2 by 2 그리고 9 by 9 CBA 패턴으로 제작되었다. 각각의 소자를 비교하면서 선택소자와 저항변화 층의 최적화된 증착 조건을 찾아내었고 극복해야할 추가적인 문제또한 확인 하였다.1. Introduction 16 1.1. Resistive switching Random Access Memory 16 1.2. Research scope and objective 20 2. Bipolar resistive switching property of Si3N4-x thin film depending on N-deficiency 22 2.1. Introduction 22 2.2. Experimental 25 2.3. Results and Discussions 26 2.4. Conclusion 45 3. Area-type electronic bipolar resistive switching of Pt/Al2O3/Si3N3.0/Ti with forming free, self-rectification, and nonlinearity characteristics 46 3.1. Introduction 46 3.2. Experimental 49 3.3. Results and Discussions 51 3.4. Conclusion 69 4. 1S1R property with Pt/Si3N4-x/TiN resistive switching device and Pt/TiO2/TiN selector device 71 4.1. Introduction 71 4.2. Experimental 73 4.3. Results and Discussions 74 4.4. Conclusion 81 5. Bibliography 82 6. Conclusion 88 List of publications 92 Abstract (in Korean) 104Docto

산화물/질화물 복합구조를 이용한 유연한 전자 및 광전소자 응용

학위논문 (박사) -- 서울대학교 대학원 : 자연과학대학 물리학과, 2020. 8. 이규철.물리적으로 강하고 유연한 그래핀과 같은 2차원 소재위에 성장된 무기물 나노소재로 구성된 복합차원 나노소재는 유연한 대면적 전자 및 광전소자로의 응용에 적합한 형태의 소재 구조이며, 실제로 이를 기반으로 한 유연한 수직형 전계효과 트랜지스터 및 발광다이오드 등을 포함한 많은 소자들이 개발되고 있다. 하지만, 처리된 정보를 저장하고 이를 사용자에게 전달하는 기능을 수행하기 위해선 보다 다양한 소자들이 개발되어야 할 필요가 있다. 본 학위논문은 이러한 수요를 충족시키기 위해, 복합차원 나노소재 기반 유연한 대면적 차세대 비휘발성 메모리 및 유연한 대면적 다파장 발광 다이오드의 개발에 대하여 다루고 있다. 복합차원 나노소재를 기반으로 차세대 비휘발성 메모리를 구현하기 위해 니켈 산화물 및 질화갈륨 이종구조로 구성된 마이크로디스크 형태의 소재를 그래핀 위에 성장하고, 본 소재의 상부 및 하부에 전극을 증착하여 전극/산화물/전극으로 구성된 형태의 산화물 기반 저항변화 메모리를 제조할 수 있었다. 마이크로디스크 형태의 소재의 사이가 떨어져있기 때문에 본 소자를 유연한 형태에서 구현하거나 1,000 회 이상의 구부림 뒤 소자의 특성을 파악할 때 소자 특성의 큰 변화 없이 정보가 안정적으로 저장되는 특성을 확인할 수 있었다. 뿐만 아니라, 니켈 산화물 기반 저항변화메모리를 동작할 때, 산화물 내부에 전도성이 높은 니켈 산화물이 필라멘트 형태로 구성되는데, 이를 발광다이오드의 나노전극으로 사용하여 저항변화메모리 내부의 필라멘트 역학에 대해서도 연구할 수 있었다. 한편, 저장된 정보를 사용자에게 정확하게 전달하기 위해선 발광다이오드의 한 픽셀 (pixel) 의 크기가 수 마이크로미터 이하로 작아야하고, 빨강, 초록, 파랑색의 빛을 발광할 수 있어야 하는데 이는 현재 이용되고 있는 픽 앤 플레이스 (pick and place) 기술을 이용하여 제조할 때 소자 제조의 효율성 및 재현성에 한계를 보이고 있다. 본 학위논문에서는 이를 극복하기 위한 방법의 하나로, 다양한 색을 발광할 수 있는 발광다이오드를 하나의 그래핀 기판위에 동시에 성장하는 방법을 제시하고 이를 유연한 다파장 발광다이오드로 구현하는 방법에 대해 기술하고 있다. 본 소자를 구현하기 위해 다양한 모양의 질화갈륨 및 산화아연 이종구조를 그래핀 위에 성장하는 방법을 개발하였는데, 산화아연 나노튜브의 간격을 다르게 설정하여 성장하고 이 위에 질화갈륨을 성장하면 질화갈륨의 성장률이 나노튜브의 간격에 따라 다르게 형성되어 다른 모양의 마이크로 발광다이오드가 성장되는 것을 이용하였다. 각기 다른 발광다이오드에 같은 전압을 가해줬을 때 성장률의 차이로 인한 다중 양자 우물 조성의 변화 및 소재 내부의 결함으로 인해 각기 다른 파장의 색이 발광되는 특성을 확인하였고, 유연한 형태에서도 안정적으로 발광특성이 유지되는 것을 확인할 수 있었다.The hybrid dimensional nanostructrures composed of high-quality inorganic nanostructures grown directly on two-dimensional (2D) materials such as graphene offers a novel material system for flexible electronics and optoelectronics. Indeed, the hybrid dimensional nanostructures have been fabricated to flexible electronics/optoelectronics and attracted many attentions with their excellent performances. Despite of the demonstration of flexible devices using the hybrid dimensional nanostructures, there remains a lot of devices that need to be further investigated in order to realize future electronics/optoelectronics such as wearable devices. This thesis presents the hybrid material system composed of oxide/nitrid heterostructures grown on graphene films and their applications on flexible non-volatile memory and flexible multi-color LEDs.Abstract Chapter 1. General Introduction 1 1.1. Motivation: Potentials of hybrid dimensional nanomaterials for flexible electronic/optoelectronic device applications 1 1.2. Thesis objective and approach 3 1.3. Thesis outline 4 Chapter 2. Literature survey 6 2.1. Oxide-based flexible electronics 6 2.1.1. Current status of oxide-based electronics 8 2.1.2. Next generation oxide-based electronics: ReRAM 12 2.1.3. Flexible ReRAM 17 2.1.3.1. ReRAM on plastic substrates 17 2.1.3.2. Transfer of ReRAM layers on flexible substrates 20 2.2. Nitride-based flexible optoelectronics 23 2.2.1. Current status of nitride-based optoelectronics 23 2.2.2. Next generation nitride-based optoelectronics: flexible & high-resolution LED 29 2.3. Hybrid dimensional material systems for flexible electronics and Optoelectronics 34 2.3.1. Growth of oxide & nitride nano-/micro-structures on graphene layers35 2.3.2. Functional devices using hybrid dimensional material Systems 45 2.3.2.1. Electronics 47 2.3.2.2. Optoelectronics 50 Chapter 3. Experimental Techniques 53 3.1. Growth techniques 53 3.1.1. Metalorganic vapor-phase epitaxy system 53 3.1.1.1. Gas delivery system 53 3.1.1.2. Reactor and temperature controller 55 3.1.1.3. Exhaust disposal system and low pressure pumping System 56 3.2. Structural characterization 57 3.2.1. Morphology inspection 57 3.2.2. Crystallographic and microstructural investigations 57 3.2.2.1. Transmission electron microscopy 57 3.3. Optical characterization 58 3.3.1. Photoluminescence & electroluminescence spectroscopy 58 3.4. Electrical characterization 59 3.4.1. Current-Voltage measurement 59 Chapter 4. Flexible ReRAM based on hybrid dimensional material systems 60 4.1. Introduction 60 4 .2. Growth of oxide/nitride hybrid structures on graphene layers 61 4.2.1. ZnO nanowall growth CVD-graphene films 62 4.2.2. Growth of GaN microdisk arrays 62 4.2.3. Growth of resistive switching layers 65 4.4. Fabrication of flexible ReRAM 65 4.5. Resistive switching characteristics 69 4.6. Discussion for the mechanism of resistive switchings using oxide/nitride hybrid structures 78 4.6.1. Fabrication of ReRAM/LED hybrid device 80 4.6.2. Real-time imaging of resistive switching dynamics 85 4.7. Summary 99 Chapter 5. Monolithic integration of morphology controlled GaN microstructures on graphene films for flexible & multi-color LEDs 101 5.1. Introduction 101 5.2. Morphology control of GaN microstructures on graphene films 103 5.2.1. Growth parameter: spacing & time 103 5.2.2. Growth behavior analysis 109 5.3. Fabrication of LEDs on graphene films 115 5.4. EL and electrical characteristics 118 5.5. High temperature operations of flexible LEDs 125 5.6. Summary 134 Chapter 6. Conclusion and Outlook 136 6.1. Conclusion 136 6.2. Future works and outlook 141 References 143 Abstract (Korean) 151Docto

The Direct Tunneling, Dielectric Breakdown Investigation, and RRAM Application in MBE Hexagonal Boron Nitride Monolayers Using Metal-Insulator-Metal Devices

In today’s post-Morre era, low-dimensional materials and their potential electronic applications have attracted extensive attention, but high-quality material synthesis and complicated device physics investigation is still challenging. Our lab is able to use Molecular Beam Epitaxy (MBE) epitaxy to reliably grow high quality millimeter grain size continuous ultrathin 2D (two-dimensional) hexagonal boron-nitridefilm (h-BN ) on Cobalt (Co) and Nickle (Ni) catalytic transition metal substrates. This is highly advantage in 2D electronic and photonic device applications. In this thesis, we report our comprehensive electric tunneling, dielectric breakdown, and memory application of single-layer h-BN film by fabricating scalable Metal-insulator-metal (MIM) diodes. Direct tunneling and dielectric breakdown in molecular beam epitaxial hexagonal boron nitride (h-BN) monolayers were studied based on Ni/h-BN/Ni device configuration in Chapter 2. Effective tunneling areas are orders of magnitude smaller than the physical areas of the devices. Statistical Weibull analysis of the breakdown characteristics shows that breakdown area-scaling law applies to the effective areas rather than physical areas of the devices. The h-BN based MIM devices can sustain repeated DC voltage sweeping stresses up to 85 times under an extremely high compliance current of 100 mA, and the critical electric field is determined to be at least 11.8 MV/cm, demonstrating high dielectric strength and reliability of these h-BN monolayers. The mechanism of the breakdown and recovery of the h-BN monolayer MIM devices is also discussed. The second project (Chapter 3) is devoted to the evaluation of Resistive Random Access Memory (RRAM) devices and the mechanism discussion of monolayer h-BN in MIM structure. The memory performance of bipolar switching shows great endurance with 97 cycles at 100mA compliance current, and a high average of 10^3 on/off ratio, but the reliability is an issue. For this particular film, both non-volatile bipolar and unipolar resistive switching (RS) and volatile threshold (TH) switching phenomena were found to coexist and could be converted from one to the other by controlling the electrical power, which provides a better understanding of the switching models. In devices with Graphene bottom electrodes, bipolar resistive switching with self-compliance current is discovered, making h-BN potential in low-power device applications

Memristive Non-Volatile Memory Based on Graphene Materials

Resistive random access memory (RRAM), which is considered as one of the most promising next-generation non-volatile memory (NVM) devices and a representative of memristor technologies, demonstrated great potential in acting as an artificial synapse in the industry of neuromorphic systems and artificial intelligence (AI), due its advantages such as fast operation speed, low power consumption, and high device density. Graphene and related materials (GRMs), especially graphene oxide (GO), acting as active materials for RRAM devices, are considered as a promising alternative to other materials including metal oxides and perovskite materials. Herein, an overview of GRM-based RRAM devices is provided, with discussion about the properties of GRMs, main operation mechanisms for resistive switching (RS) behavior, figure of merit (FoM) summary, and prospect extension of GRM-based RRAM devices. With excellent physical and chemical advantages like intrinsic Young’s modulus (1.0 TPa), good tensile strength (130 GPa), excellent carrier mobility (2.0 × 105 cm2∙V−1∙s−1), and high thermal (5000 Wm−1∙K−1) and superior electrical conductivity (1.0 × 106 S∙m−1), GRMs can act as electrodes and resistive switching media in RRAM devices. In addition, the GRM-based interface between electrode and dielectric can have an effect on atomic diffusion limitation in dielectric and surface effect suppression. Immense amounts of concrete research indicate that GRMs might play a significant role in promoting the large-scale commercialization possibility of RRAM devices

RESISTIVE SWITCHING CHARACTERISTICS OF NANOSTRUCTURED AND SOLUTION-PROCESSED COMPLEX OXIDE ASSEMBLIES

Miniaturization of conventional nonvolatile (NVM) memory devices is rapidly approaching the physical limitations of the constituent materials. An emerging random access memory (RAM), nanoscale resistive RAM (RRAM), has the potential to replace conventional nonvolatile memory and could foster novel type of computing due to its fast switching speed, high scalability, and low power consumption. RRAM, or memristors, represent a class of two terminal devices comprising an insulating layer, such as a metal oxide, sandwiched between two terminal electrodes that exhibits two or more distinct resistance states that depend on the history of the applied bias. While the sudden resistance reduction into a conductive state in metal oxide insulators has been known for almost 50 years, the fundamental resistive switching mechanism is a complex phenomenon that is still long-debated, complex process. Further improvements to existing memristor performance require a complete understanding of memristive properties under various operation conditions. Additional technical issues also remain, such as the development of facile, low-cost fabrication methods as an alternative to expensive, ultra-high vacuum (UHV) deposition methods. This collection of work explores resistive switching within metal oxide-based memristive material assemblies by analyzing the fundamental physical insulating material properties. Chapter 3 aims to translate the utility and simplicity of the highly ordered anodic aluminum oxide (AAO) template structure to complex, yet more functional (memristive) materials. Functional oxides possessing ordered, scalable nanoporous arrays and nanocapacitor arrays over a large area is of interest to both the fields of next-generation electronics and energy storing/harvesting devices. Here their switching performance will be evaluated using conductive atomic force microscopy (C-AFM). Chapter 4 demonstrates a convective self-assembly fabrication method that effectively enables the synthesis of a low-cost solution processed memristor comprising binary oxide and perovskite ABO3 nanocrystals of varying diameter. Chapter 5 systematically compares the influence of inter-nanoparticle distance on the threshold switching SET voltage of hafnium oxide (HfO2) memristors. Utilizing shorter phosphonic acid ligands with higher binding affinity on the nanocrystal surface enabled a record-low SET voltage to be achieved. Chapter 6 extends the scope to the fine tuning of solution processed memristors with two types of perovskites nanocrystals. The primary advantage of nanocrystal memristors is the ability to draw from additional degrees of freedom by tuning the constituent nanocrystal material properties. Recent advancement of solution phase techniques enables a high degree of controllability over the nanocrystal size and structure. Thus, this work found in this dissertation aims to understand and decouple the effects of the geometric size and substitutional nanocrystal parameters on resistive switching