Student Seminar Session: Applied Physics (2/2)

Wednesday 13 Mar 2024, 15:00 → 17:30 Europe/Madrid

Semisotano parque científico, sala SS6, bajo el IFIC

15:00 – 15:30 Ismael Fernández Guillén

Tittle: Harnessing Monocrystal Perovskites for Memristor Applications: A Promising Frontier in Neuromorphic Computing

The integration of perovskite materials into memristor devices heralds a new era in neuromorphic computing, offering unprecedented opportunities for efficient information processing and storage. Perovskite-based memristors leverage the unique electronic properties of these materials, including high carrier mobility, tunable bandgap, and facile ion migration. This abstract explores the burgeoning field of perovskite memristors, highlighting their remarkable attributes such as non-volatile resistive switching, low energy consumption, and compatibility with large-scale fabrication processes. Additionally, the synergistic combination of perovskite memristors with emerging technologies like artificial intelligence and brain-inspired computing architectures holds immense potential for realizing energy-efficient, brain-inspired computing systems. Through elucidating the advantages and recent advancements in perovskite-based memristors, this abstract aims to catalyze further research and innovation in the field, paving the way for next-generation computing paradigms. In this context, monocrystalline perovskites offer distinct advantages over polycrystalline counterparts in the field of memristors. Their precisely ordered atomic structure facilitates superior charge transport properties, resulting in enhanced memristive behavior, such as lower switching voltages and improved retention characteristics. Moreover, the absence of grain boundaries in single crystals minimizes defect-induced scattering and ensures uniform device performance. This abstract underscores the significance of monocrystalline perovskites in advancing memristor technology by exploiting their inherent structural integrity and electronic properties.

15:30 – 16:00 Pablo Franco Betancour

Tittle: Unconventional low-frequency features in the impedance spectroscopy response of metal halide perovskites-based systems

Impedance spectroscopy (IS) has been a valuable tool for characterizing photovoltaic and optoelectronic devices. This technique enables the frequency splitting of the main features, allowing the study of charge and ionic processes independently and providing detailed information on the dynamics involved in the device’s operation. However, the interpretation of the IS data for perovskite remains challenging due to the number of dynamic processes having places both in the interfaces and the bulk. In this work, we focused on analyzing the different behaviors found in impedance spectra at low-frequency domains in relation to devices working ranges, architectures, and perovskite composition.

Coffe break

16:15 – 16:45 Miriam Mínguez Avellán

Tittle: Exploiting Perovskite’s Kryptonite: A humidity treatment for efficient photocatalysts

Lead-halide perovskites are a very promising family of materials due to their optoelectronic properties and chemical versatility. These characteristics make them suitable for very different applications such as solar cells, light-emitting diodes (LEDs), photodetectors or photocatalysts. Despite this, one of the main drawbacks of perovskite materials is stability. Their behaviour against moisture, temperature and UV light is critical, causing accelerated decomposition and degradation of the material. To address these main drawbacks, the in-situ synthesis of perovskite materials inside a host matrix emerges as a very promising alternative. In this talk, I will present a two-step process to synthesize MAPbI3 nanocrystals embedded in a Ni(AcO)2 matrix only using humidity as driven force for the crystallization and their photocatalytic properties.

16:45 – 17:15 Omar Eduardo Solís Luna

Tittle: Improving the performance and stability of Sn-based perovskite solar cells

Tin-based halide perovskites(Sn-HPs) have shown great attention due to their optoelectronic properties, high photoconversion efficiency and low toxicity compared to Lead-based perovskites. However, one of the primary problems of Sn-HPs is the easy oxidation of Sn2+ into Sn+4 that promotes tin vacancies in the perovskite structure, which leads to a poor film morphology and degradation mechanisms that compromises the device performance and stability. Nevertheless, this problem can be mitigated with the use of reducing agents, antioxidants and bulky ammonium cations (2D cations). The addition of 2D cations into the perovskite structure provides better stability and a slower oxidation, due to its high hydrophobicity. In this work, we have incorporated  2-thiopheneethylammonium (TEA) as 2D cation into FASnI3 perovskite , leading to the formation of a 2D/3D perovskite structure. This approach entails high quality films and a lower concentration of Sn4+ on the surface. Which improves the device performance and stability even in ambient conditions, in comparison with the reference device of pure FASnI3.