MoS2 기반의 휘어지는 비휘발성 메모리

학위논문 (석사)-- 서울대학교 대학원 : 화학생물공학부, 2017. 2. 김대형.An importance of flexible memory has increased due to internet of things (IoT) and wearable devices. And there has also been requirement of development of novel memory because of downscaling of dynamic random access memory (DRAM). A resistive random access memory (RRAM) among the next-generation memories achieved high quality properties using molybdenum disulfide (MoS2). Molybdenum disulfide has been considered as an emerging semiconducting material for post-silicon electronics. Although extensive efforts to uniformly control thickness of MoS2 through chemical vapor deposition have achieved, wafer-scale preparation is still challenging. Here, I present wafer-scale flexible resistive random access memory (RRAM) using colloidal MoS2 nanosheets which act as a resistive switching layer. Filamentary resistive switching of partially oxidized MoS2/MoOx hetero-structures is resulted from Poole-Frenkel conduction. MoS2-based RRAM arrays show the high on/off ratios. The wafer-scale RRAM arrays show uniform physical and electrical characteristics regardless of locations. Representative examples demonstrate a novel user-interactive application with optical readability which enables external pressures to be stored and then visualized by quantum dot light emitting diode (QDLED) arrays. Integration strategy allows the MoS2 hetero-structure to be a stepping stone for enhancing performances of existing wearable data storage systems. This study provides breakthroughs in next-generation flexible memory using new semiconducting materials.1. Introduction 1 2. Wafer-scale integration of MoS2 nanosheets 4 2.1 Wafer-scale integration of the MoS2 nanosheets 4 2.2 Characterization of wafer-scale resistive memory 9 2.3 1D1R array 13 2.4 Flexibility test 19 3. System-lever demonstration for optical readability 25 3.1 Mechanical data storage system 25 3.2 Optical data read system 30 4. Experimental Section 34 4.1 Fabrication MoS2-based devices 34 4.2 Spray coating of MoS2 nanosheets 35 4.3 Fabrication of QLED arrays 35 5. Conclusion 37 6. References 38 요약(국문초록) 40Maste