Istituto Italiano di Tecnologia

About: Istituto Italiano di Tecnologia is a facility organization based out in Genoa, Italy. It is known for research contribution in the topics: Robot & Humanoid robot. The organization has 4561 authors who have published 14595 publications receiving 437558 citations. The organization is also known as: Italian Institute of Technology & IIT.

Photoinduced Emissive Trap States in Lead Halide Perovskite Semiconductors

Abstract: The recent success of lead halide perovskites is given by their optimal primary optoelectronic properties relevant for photovoltaic and, more in general, for optoelectronic applications. However, a lack of knowledge about the nature of instabilities currently represents a major challenge for the development of such materials. Here we investigate the luminescence properties of polycrystalline thin films of lead halide perovskites as a function of the excitation density and the environment. First we demonstrate that in an inert environment photoinduced formation of emissive sub-band gap defect states happens, independently of the chemical composition of the lead halide semiconductor, which quenches the band-to-band radiative emission. Carrier trapping occurs in the subnanosecond time regime, while trapped carriers recombine in a few microseconds. Then, we show that the presence of oxygen, even in a very small amount, is able to compensate such an effect.

BiVO4 as photocatalyst for solar fuels production through water splitting: A short review

Abstract: As solar energy is the most abundant energy source, it has been widely exploited for thermal and electrical power generation. However, owing to the greater convenience of chemical energy storage, such as H 2 , compared to electricity, solar fuels have been considered as one of the most promising technological concepts due to their potential higher efficiency and environmental suitability. In this context, the photocatalytic water splitting into O 2 and solar fuels ( e.g. H 2 ) is a topic of current interest. Furthermore, the development of photocatalysts that can utilize the whole electromagnetic spectrum is preferable in order to enhance the overall water splitting efficiency. Direct photocatalytic water splitting is a challenging problem because the water oxidation (WO) reaction is thermodynamically uphill. Hence, several WO photocatalysts have been developed and assessed over the last few decades, and it has been reported that BiVO 4 is one of the most active O 2 evolution photocatalysts. In this review, a first introduction regarding the solar fuel production and the water oxidation reaction is reported. Subsequently, the crystal and electronic structures as well as the optical properties that are closely related to the photoelectrochemical properties of BiVO 4 are described. Finally, the monoclinic BiVO 4 synthesis methods and the optimization methods to improve the performances of BiVO 4 are discussed. The information gained from this analysis contributes to the better understanding of the main parameters affecting the activity and will ultimately lead to the optimized synthesis of a more efficient BiVO 4 photocatalytic material.

Simultaneous Cationic and Anionic Ligand Exchange For Colloidally Stable CsPbBr3 Nanocrystals

Abstract: Postsynthesis ligand exchange has been employed extensively on lead halide perovskite (LHP) nanocrystals (NCs), but the complex ligand shell composition of the starting NCs prevented a clear understanding of the exchange process, and the surface chemistry of the final NCs remained poorly characterized. Here, we describe a ligand exchange strategy involving the displacement of both cationic and anionic ligands on native model systems of CsPbBr3 NCs, which are exclusively coated with Cs-oleate. These ligands are exchanged with various quaternary ammonium bromides (R4NBr), and complete exchange is confirmed by nuclear magnetic resonance (NMR) spectroscopy analysis. The displacement of the native Cs-oleate ligands with proton-free R4NBr delivers NCs with excellent colloidal stability and near-unity PLQY, which is preserved after washing with polar solvents, over 3 weeks of storage in air, and after heating a solution of NCs to 80 °C, as confirmed by NMR analysis. The results, together with density functional ...

Affordances in Psychology, Neuroscience, and Robotics: A Survey

Abstract: The concept of affordances appeared in psychology during the late 60s as an alternative perspective on the visual perception of the environment. It was revolutionary in the intuition that the way living beings perceive the world is deeply influenced by the actions they are able to perform. Then, across the last 40 years, it has influenced many applied fields, e.g., design, human-computer interaction, computer vision, and robotics. In this paper, we offer a multidisciplinary perspective on the notion of affordances. We first discuss the main definitions and formalizations of the affordance theory, then we report the most significant evidence in psychology and neuroscience that support it, and finally we review the most relevant applications of this concept in robotics.