# Nonvolatile Organic Floating-Gate Memory Using N2200 as Charge-Trapping Layer
## 1 Introduction  
Nonvolatile organic field-effect transistor memories (OFETMs) have attracted considerable attention due to their advantages, including low cost, large area, easy processing, light weight, and good compatibility with flexible substrates, so they have extensive prospects of applications ranging from sensors and flexible displays to wearable electronic devices [1, 2, 3, 4]. With the advent of the post-Moore era, conventional silicon flash memory technologies are facing the quantum limit of the so-called Moore's law, which states that the charges stored in floating-gate structures are susceptible to leakage in the 10 nm range. Emerging memory technologies are reshaping the data storage space by moving beyond traditional transistor-based architectures. For example, resistive memory (ReRAM) [5] utilizes changes in material resistance to achieve high density, low power, and fast storage. Phase-change memory (PCM) [6] utilizes transitions between amorphous and crystalline states to provide scalability and endurance. Magnetic memories (MRAM and STT-MRAM) [7] rely on magneto-resistive effects for nonvolatile and high-speed operation, and spin-orbit torque MRAM (SOT-MRAM) further improves writing efficiency. Ferroelectric memory (FeRAM) [8] exploits the polarization properties of ferroelectric materials to achieve energy-efficient, fast, and nonvolatile storage. In addition, optical and quantum memories [9, 10] explore innovative paradigms for high-performance systems using optical longitudinal and quantum states. Compared to two-terminal memory [11], three-terminal OFETM has many advantages, such as the fact that one does not need to add other circuit components to select the target cell [12], and one can perform accurate charge modulation,non-destructive readout, and multi-bit storage. According to different memory mechanisms, OFETM can be classified into floating-gate OFETM (FG-OFETM), ferroelectric OFETM (Fe-OFETM), and polymer electret OFETM (PE-OFETM) [13; 14; 15; 16]. Fe-OFETM uses a ferroelectric material as the gate dielectric. The polarization state of the ferroelectric insulator is changed by applying an external voltage, thereby accurately adjusting the carrier concentration in the channel. Therefore, the \"0\" and \"1\" states can be read out with a lossless drain current. Although Fe-OFETM has many potential advantages, such as fast reading and writing speeds and low power consumption during programming and erasing, ferroelectric materials usually have rough surface morphology [17], and due to the semi-crystalline nature of the material, the programming and erasing time is longer and the retention time is relatively shorter compared to FG-OFETM. PE-OFETM also has potential advantages, such as polymer electret materials having good flexibility, a low cost of raw materials, and a simple manufacturing process. However, the stability of polymer materials is susceptible to environmental factors, which may lead to performance degradation in long-term use. Moreover, the reading and writing speed is slower than that of other types of memory. Compared with Fe-OFETM and PE-OFETM, FG-OFETM has attracted much attention because it is endowed with a more stable data retention capability and excellent fatigue resistance [18; 19; 20; 21; 22]. Over the past decade, research on FG-OFETM has mainly focused on manufacturing and optimizing the performance of floating-gate (FG) materials. When nanoparticles (NPs) are used as the FG layer, the memory performance of FG-OFETM can be enhanced by adjusting the size of NPs and the distribution density in the FG layer. Commonly used materials include metal NPs [23], quantum dots [24], inorganic NPs [25], and organic NPs [26]. [PERSON] et al.