電阻式記憶體（Resistive Random Access Memory，RRAM）被視為取代快閃記憶體的次世代記憶體之一。在本篇論文中，我們製造了以旋轉塗佈法沉積的有機無機雜化鈣鈦礦(MAPbBr3)與無機鈣鈦礦(CsPbBr3)為介電層的電阻式記憶體。以銫離子替換甲胺基離子形成的無機電阻式記憶體元件，該元件展示了4個數量級(1.6x104)的高開關電流比，以及300次電阻切換行為，設置電壓為0.7伏特，復位電壓為-1.4伏特，並大幅改善對環境的容忍度。利用兩種不同的上電極金屬(鋁、金)釐清電阻轉換行為的可能機制。除此之外，調整旋塗法的速率與浸泡時間來改變鈣鈦礦薄膜的厚度與表面形貌，並施加電性量測比較不同厚度對元件的操作電壓、高低電阻值與電阻切換次數等特性的影響，以及探討高電阻態與低電阻態的電流傳導機制以及傳導燈絲(conductive filament)的性質。 製造以PEDOT:PSS為中間層的元件，證明電阻切換行為來自鈣鈦礦薄膜。
以X光電子能譜儀（X-ray Photoelectron Spectroscopy，XPS）及X光繞射分析(X-ray diffraction analysis, XRD) 分析鈣鈦礦薄膜的晶粒大小及表面粗糙度，並以掃描式電子顯微鏡（Scanning Electron Microscopy, SEM）確認元件的結構，以兩步旋塗法製備之鈣鈦礦薄膜若未經過完全轉化，會導致針孔大量存在於薄膜表面，造成元件的記憶體特性劣化。

Resistive random-access memory (RRAM) is regarded as one of the next-generation memories to replace flash memory. In this paper, we fabricated organic-inorganic hybrid perovskite (MAPbBr3) and inorganic perovskite (CsPbBr3) deposited by spin coating as the dielectric layer of resistive memory device. An inorganic resistive memory device formed by replacing methylamine ion with cesium ion shows a high switching current ratio of 104 (1.6x104) and 300 resistance switching behaviors. Two different top electrode metals (aluminum, gold) are used to clarify the possible mechanism of resistance switching behavior. In addition, the thickness and surface morphology of the perovskite film are changed by adjusting the spin-rate and immersing time of the spin coating method, and electrical measurements are applied to compare the operating voltage, high and low resistance values and switching cycles of the device with different thicknesses. And to explore the current conduction mechanism of high resistance state and low resistance state and the properties of conductive filament. A device with PEDOT: PSS as the active layer was fabricated to prove that the resistance switching behavior came from the perovskite film.
X-ray Photoelectron Spectroscopy (XPS) and X-ray diffraction analysis (XRD) were used to analyze the grain size and surface roughness of the perovskite film, scanning electron microscopy (SEM) is used to confirm the structure of the device. If the perovskite film prepared by the two-step spin coating method is not completely converted, a large number of pinholes will exist on the surface of the film, which will cause the device memory characteristics deteriorate.

[1] B. Govoreanu, D. Brunco, and J. Van Houdt, "Scaling down the interpoly dielectric for next generation flash memory: Challenges and opportunities," Solid-State Electronics, vol. 49, no. 11, pp. 1841-1848, 2005.
[2] G. Muller, T. Happ, M. Kund, G. Y. Lee, N. Nagel, and R. Sezi, "Status and outlook of emerging nonvolatile memory technologies," in IEDM Technical Digest. IEEE International Electron Devices Meeting, 2004., 2004: IEEE, pp. 567-570.
[3] T. Mikolajick et al., "FeRAM technology for high density applications," Microelectronics Reliability, vol. 41, no. 7, pp. 947-950, 2001.
[4] K. Inomata, "Present and future of magnetic RAM technology," IEICE transactions on electronics, vol. 84, no. 6, pp. 740-746, 2001.
[5] S. Bhatti, R. Sbiaa, A. Hirohata, H. Ohno, S. Fukami, and S. Piramanayagam, "Spintronics based random access memory: a review," Materials Today, vol. 20, no. 9, pp. 530-548, 2017.
[6] S. Raoux, F. Xiong, M. Wuttig, and E. Pop, "Phase change materials and phase change memory," MRS bulletin, vol. 39, no. 8, pp. 703-710, 2014.
[7] A. P. Ferreira, B. Childers, R. Melhem, D. Mossé, and M. Yousif, "Using PCM in next-generation embedded space applications," in 2010 16th IEEE Real-Time and Embedded Technology and Applications Symposium, 2010: IEEE, pp. 153-162.
[8] B. Choi et al., "Resistive switching mechanism of TiO 2 thin films grown by atomic-layer deposition," Journal of applied physics, vol. 98, no. 3, p. 033715, 2005.
[9] W.-Y. Chang, Y.-C. Lai, T.-B. Wu, S.-F. Wang, F. Chen, and M.-J. Tsai, "Unipolar resistive switching characteristics of ZnO thin films for nonvolatile memory applications," Applied Physics Letters, vol. 92, no. 2, p. 022110, 2008.
[10] D. Ielmini, F. Nardi, and C. Cagli, "Physical models of size-dependent nanofilament formation and rupture in NiO resistive switching memories," Nanotechnology, vol. 22, no. 25, p. 254022, 2011.
[11] Y. Cai, J. Tan, L. YeFan, M. Lin, and R. Huang, "A flexible organic resistance memory device for wearable biomedical applications," Nanotechnology, vol. 27, no. 27, p. 275206, 2016.
[12] S. Yu, "Overview of resistive switching memory (RRAM) switching mechanism and device modeling," in 2014 IEEE International Symposium on Circuits and Systems (ISCAS), 2014: IEEE, pp. 2017-2020.
[13] K.-M. Chang, W.-H. Tzeng, K.-C. Liu, and W.-R. Lai, "Modulation of the electrical characteristics of HfOx/TiN RRAM devices through the top electrode metal," ECS Transactions, vol. 28, no. 2, p. 119, 2010.
[14] I. Chakraborty, N. Panwar, A. Khanna, and U. Ganguly, "Space Charge Limited Current with Self-heating in Pr $ _ {0.7} $ Ca $ _ {0.3} $ MnO $ _3 $ based RRAM," arXiv preprint arXiv:1605.08755, 2016.
[15] L. C. Schmidt et al., "Nontemplate synthesis of CH3NH3PbBr3 perovskite nanoparticles," Journal of the American Chemical Society, vol. 136, no. 3, pp. 850-853, 2014.
[16] Y. K. Chih et al., "NiOx electrode interlayer and CH3NH2/CH3NH3PbBr3 Interface treatment to markedly advance hybrid perovskite‐based light‐emitting diodes," Advanced materials, vol. 28, no. 39, pp. 8687-8694, 2016.
[17] Q. Chen et al., "Planar heterojunction perovskite solar cells via vapor-assisted solution process," Journal of the American Chemical Society, vol. 136, no. 2, pp. 622-625, 2014.
[18] Y. H. Lee, D. H. Kim, C. Wu, and T. W. Kim, "Memristive devices with a large memory margin based on nanocrystalline organic-inorganic hybrid CH3NH3PbBr3 perovskite active layer," Organic Electronics, vol. 62, pp. 412-418, 2018.
[19] L. Reimer, "Scanning electron microscopy: physics of image formation and microanalysis," ed: IOP Publishing, 2000.
[20] J. Epp, "X-ray diffraction (XRD) techniques for materials characterization," in Materials characterization using nondestructive evaluation (NDE) methods: Elsevier, 2016, pp. 81-124.
[21] J. D. Andrade, "X-ray photoelectron spectroscopy (XPS)," in Surface and interfacial aspects of biomedical polymers: Springer, 1985, pp. 105-195.
[22] D. Pawlak, T. Lukasiewicz, M. Carpenter, M. Malinowski, R. Diduszko, and J. Kisielewski, "Czochralski crystal growth, microstructure and spectroscopic properties of PrAlO3 perovskite," Journal of crystal growth, vol. 282, no. 1-2, pp. 260-269, 2005.
[23] M. M. Tavakoli et al., "Fabrication of efficient planar perovskite solar cells using a one-step chemical vapor deposition method," Scientific reports, vol. 5, p. 14083, 2015.
[24] Q. Wang, Y. Shao, Q. Dong, Z. Xiao, Y. Yuan, and J. Huang, "Large fill-factor bilayer iodine perovskite solar cells fabricated by a low-temperature solution-process," Energy & Environmental Science, vol. 7, no. 7, pp. 2359-2365, 2014.
[25] M. A. Najeeb et al., "Growth of MAPbBr3 perovskite crystals and its interfacial properties with Al and Ag contacts for perovskite solar cells," Optical Materials, vol. 73, pp. 50-55, 2017.
[26] D. Lee, B. Hwang, and J.-S. Lee, "Impact of grain sizes on programmable memory characteristics in two-dimensional organic–inorganic hybrid perovskite memory," ACS applied materials & interfaces, vol. 11, no. 22, pp. 20225-20231, 2019.
[27] X. Cao et al., "Enhanced switching ratio and long-term stability of flexible RRAM by anchoring polyvinylammonium on perovskite grains," ACS applied materials & interfaces, vol. 11, no. 39, pp. 35914-35923, 2019.
[28] C. Sun, S. Lu, F. Jin, W. Mo, J. Song, and K. Dong, "The Resistive Switching Characteristics of TiN/HfO 2/Ag RRAM Devices with Bidirectional Current Compliance," Journal of Electronic Materials, vol. 48, no. 5, pp. 2992-2999, 2019.
[29] K.-H. Chen et al., "Schottky emission distance and barrier height properties of bipolar switching Gd: SiOx RRAM devices under different oxygen concentration environments," Materials, vol. 11, no. 1, p. 43, 2018.
[30] J. Choi et al., "Organolead halide perovskites for low operating voltage multilevel resistive switching," Advanced Materials, vol. 28, no. 31, pp. 6562-6567, 2016.
[31] Q. Lin et al., "Transient resistive switching memory of CsPbBr3 thin films," Advanced Electronic Materials, vol. 4, no. 4, p. 1700596, 2018.
[32] X. Chang et al., "Carbon-based CsPbBr3 perovskite solar cells: all-ambient processes and high thermal stability," ACS applied materials & interfaces, vol. 8, no. 49, pp. 33649-33655, 2016.
[33] P. Cheng et al., "One-step solution deposited all-inorganic perovskite CsPbBr3 film for flexible resistive switching memories," Applied Physics Letters, vol. 115, no. 22, p. 223505, 2019.
[34] J. Lei et al., "Efficient planar CsPbBr3 perovskite solar cells by dual-source vacuum evaporation," Solar Energy Materials and Solar Cells, vol. 187, pp. 1-8, 2018.
[35] C. Gu and J.-S. Lee, "Flexible hybrid organic–inorganic perovskite memory," ACS nano, vol. 10, no. 5, pp. 5413-5418, 2016.
[36] L. Qiu, L. K. Ono, and Y. Qi, "Advances and challenges to the commercialization of organic–inorganic halide perovskite solar cell technology," Materials today energy, vol. 7, pp. 169-189, 2018.
[37] B. J. Roman, J. Otto, C. Galik, R. Downing, and M. Sheldon, "Au Exchange or Au Deposition: Dual Reaction Pathways in Au–CsPbBr3 Heterostructure Nanoparticles," Nano letters, vol. 17, no. 9, pp. 5561-5566, 2017.
[38] S. K. Balakrishnan and P. V. Kamat, "Au–CsPbBr3 hybrid architecture: anchoring gold nanoparticles on cubic perovskite nanocrystals," ACS Energy Letters, vol. 2, no. 1, pp. 88-93, 2017.
[39] Y. Li, H. Huang, Y. Xiong, S. V. Kershaw, and A. L. Rogach, "Reversible transformation between CsPbBr 3 and Cs 4 PbBr 6 nanocrystals," CrystEngComm, vol. 20, no. 34, pp. 4900-4904, 2018.
[40] H. Cai, G. Ma, Y. He, L. Lu, J. Zhang, and H. Wang, "Compact pure phase CsPbBr3 perovskite film with significantly improved stability for high-performance memory," Ceramics International, vol. 45, no. 1, pp. 1150-1155, 2019.
[41] Y. Wu et al., "Capping CsPbBr 3 with ZnO to improve performance and stability of perovskite memristors," Nano Research, vol. 10, no. 5, pp. 1584-1594, 2017.