Electroforming-free resistive switching in spray-deposited SrTiO3 thin films with time series analysis for memory devices

초록

Strontium titanate (ST) thin films were fabricated through a cost-effective chemical spray pyrolysis technique (CSPT) by varying substrate temperature from 300 to 375 degrees C on quartz (SiO2) substrate. The device Ag/ST/FTO/ SiO2 exhibits electroforming-free quasi digital type bipolar resistive switching (BRS) at low operating voltage (+1.5 V) with symmetric current-voltage (I-V) characteristics. The fabricated device shows low switching voltages (similar to+1 V), endurance over 3 x 10(3) cycles, and data retention for 4 x 10(3) s, demonstrating its suitability for long-term, energy-efficient memory device. EDS, PL, and XPS studies confirmed oxygen deficiency in the deposited thin films, revealing that oxygen vacancies and Ag+ ions combined form and rupture conductive filaments under applied bias. The electrochemical metallization (ECM) and oxygen vacancies redistribution governs the switching process, enabling stable, low-voltage RS. Statistical analysis confirmed less variability in switching voltages with coefficient of variance (CV) is less than 12% for SET and 5% for RESET voltages. A time series analysis (TSA) based on a Long Short-Term Memory (LSTM) neural network accurately forecasted the temporal SET and RESET voltage behavior, enabling predictive performance of RS devices. These results highlight potential of SrTiO3 as a promising material for energy-efficient and scalable non-volatile memory applications.

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