Publications de Massimo Spina | EPFL Graph Search

Highly flexible CH3NH3PbI3 micro- and nanowires

Luca Rossi, László Forró, Raphaël Foschia, Luka Ciric, Massimo Spina, Endre Horvath, Márton Kollár

CH3NH3PbI3 is known to be very efficient in photon to electron conversion, which makes it extremely popular in opto-electronic applications ranging from solar cells to photodetectors. The material is very brittle in bulk, single crystalline, and thin film ...

AIP Publishing2021

Tuning ferromagnetism at room temperature by visible light

László Forró, Bálint Náfrádi, Massimo Spina, Endre Horvath, Xavier François Mettan, Andrea Pisoni, Péter Szirmai

Most digital information today is encoded in the magnetization of ferromagnetic domains. The demand for ever-increasing storage space fuels continuous research for energy-efficient manipulation of magnetism at smaller and smaller length scales. Writing a b ...

National Academy of Sciences2020

Thermal coarsening of individual titanate nanowires and their assemblies: Surface vs. bulk diffusion

Luca Rossi, László Forró, Xavier Berdat, Massimo Spina, Endre Horvath, Laurent Syavoch Bernard, Sergiy Katrych

The thermal coarsening of titanate nanowires was investigated from room temperature to 1000 degrees C by AFM, SEM, XRD and Raman spectroscopy. Phase transformation kinetics and the external morphology were studied in two configurations: i) as individual an ...

2020

Mechanical response of CH3NH3PbI3 nanowires

László Forró, Bálint Náfrádi, Martial Duchamp, Luka Ciric, Massimo Spina, Endre Horvath, Márton Kollár

AIP American Institute of Physics2018

Nanowires of organic-inorganic perovskites

László Forró, Massimo Spina, Endre Horvath

An organic-inorganic perovskite CH3NH3PbI3 nanowire showing a length-width aspect ratio from 5-400 up to 109 and a width-height ratio of 1-100 up to 1-10000. Further, the invention is embodied as a process for making the nanowire wherein at least a polar a ...

2017

Cyan titania nanowires: Spectroscopic study of the origin of the self-doping enhanced photocatalytic activity

László Forró, Richard Gaal, Arnaud Magrez, Alla Arakcheeva, Bálint Náfrádi, Xavier Berdat, Jacim Jacimovic, Massimo Spina, Endre Horvath, Laurent Syavoch Bernard, Péter Szirmai

We report a detailed spectroscopic study of Ti3+ self-doped TiO2 nanowires prepared by high temperature annealing of the protonated titanate nanowires (TiONW) in hydrogen atmosphere. Hydrogenation causes a color change from white to cyan and a major increa ...

Elsevier2017

Photodiode Response in a CH3NH3PbI3/CH3NH3SnI3 Heterojunction

László Forró, Bálint Náfrádi, Massimo Spina, Endre Horvath, Karoly Holczer, Andrea Pisoni

Here we report another surprising feature of the methylammonium metal halide material family, the phototunability of the diode response of a heterojunction made of CH3NH3PbI3 and its close relative, CH3NH3SnI3. In the dark state the device behaves as a dio ...

2017

Mechanical signatures of degradation of the photovoltaic perovskite CH3NH3PbI3 upon water vapor exposure

László Forró, Ayat Karimi, Wanda Andreoni, Bálint Náfrádi, Massimo Spina, Endre Horvath

We report on the mechanical properties of CH3NH3PbI3 photovoltaic perovskite measured by nanoindentation. The Young's modulus (E) of the pristine sample is 20.0 +/- 1.5GPa, while the hardness (H) is 1.0 +/- 0.1GPa. Upon extended exposure to water vapor, bo ...

2017

Organic-inorganic hybrid perovskite CH3NH3PbI3: structural consequences of water absorption

László Forró, Alla Arakcheeva, Massimo Spina, Endre Horvath

IUCr/Wiley2016

Ultrasensitive 1D field-effect phototransistors: CH3NH3PbI3 nanowire sensitized individual carbon nanotubes

László Forró, Richard Gaal, Bálint Náfrádi, Massimo Spina, Endre Horvath, Eric Joseph Bonvin

Field-effect phototransistors were fabricated based on individual carbon nanotubes (CNTs) sensitized by CH3NH3PbI3 nanowires (MAPbI(3)NWs). These devices represent light responsivities of R = 7.7 x 10(5) A W-1 under low-lighting conditions in the nW mm(-2) ...

2016

Controlled growth of CH3NH3PbI3 nanowires in arrays of open nanofluidic channels

László Forró, Andrzej Sienkiewicz, Bálint Náfrádi, Massimo Spina, Endre Horvath, Eric Joseph Bonvin

Spatial positioning of nanocrystal building blocks on a solid surface is a prerequisite for assembling individual nanoparticles into functional devices. Here, we report on the graphoepitaxial liquid-solid growth of nanowires of the photovoltaic compound CH ...

Nature Research2016

Rapid thickness reading of CH3NH3PbI3 nanowire thin films from color maps

László Forró, Claudio Grimaldi, Bálint Náfrádi, Massimo Spina, Endre Horvath

Hybrid halide perovskite photovoltaic materials show a remarkable light conversion efficiency in various optoelectronic devices. In the fabrication of these solar cells, light emitting diodes, laser and photodetector prototypes the thickness of the perovsk ...

Wiley-VCH Verlag2016

Optically switched magnetism in photovoltaic perovskite CH3NH3(Mn:Pb)I-3

László Forró, Oleg Yazyev, Alla Arakcheeva, Bálint Náfrádi, Massimo Spina, Endre Horvath, Péter Szirmai

The demand for ever-increasing density of information storage and speed of manipulation boosts an intense search for new magnetic materials and novel ways of controlling the magnetic bit. Here, we report the synthesis of a ferromagnetic photovoltaic CH3NH3 ...

Nature Publishing Group2016

CH3NH3PbI3: precise structural consequences of water absorption at ambient conditions

László Forró, Alla Arakcheeva, Massimo Spina, Endre Horvath

The crystal structure of the pristine (I) and aged (II) crystals of CH3NH3PbI3 (hereafter MAPbI(3)) hybrid organic-inorganic lead iodide has been studied at 293 K with high-precision single-crystal X-ray diffraction using a synchrotron light source. We sho ...

Int Union Crystallography2016

Tuning of the Thermoelectric Figure of Merit of CH3NH3MI3 (M=Pb,Sn) Photovoltaic Perovskites

László Forró, Davor Pavuna, Bálint Náfrádi, Massimo Spina, Endre Horvath, Xavier François Mettan, Andrea Pisoni, Péter Krisztián Matus, Riccardo Pisoni

The hybrid halide perovskites, the very performant compounds in photovoltaic applications, possess large Seebeck coefficient and low thermal conductivity, making them potentially interesting high figure of merit (ZT) materials. For this purpose, one needs ...

American Chemical Society2015

Hybrid Halide Perovskite Nanostructures : beyond Photovoltaics

Massimo Spina

Hybrid organometallic halide perovskites have been intensively investigated in the past few years, especially the CH3NH3PbI3, as highly efficient light harvesters for various optoelectronic application both for sensing and emitting light. However, despite ...

EPFL2015

Microengineered CH3NH3PbI3 Nanowire/Graphene Phototransistor for Low-Intensity Light Detection at Room Temperature

László Forró, Richard Gaal, Arnaud Magrez, Bálint Náfrádi, Massimo Spina, Endre Horvath, Laurent Syavoch Bernard, Mario Joe Lehmann, Eric Joseph Bonvin

The first hybrid phototransistors are reported where the performance of a network of photoactive CH3NH3PbI3 nanowires is enhanced by CVD-grown monolayer graphene. These devices show responsivities as high as ≈2.6 × 106 A W- ...

2015

Nanowires of Methylammonium Lead Iodide (CH(3)NH(3)Pbl(3)) Prepared by Low Temperature Solution-Mediated Crystallization

László Forró, Richard Gaal, Massimo Spina, Endre Horvath

We report the synthesis of Methylammonium Lead Iodide (CH3NH3PbI3) nanowires by a low temperature solution processed crystallization using a simple slip-coating method. The anisotropic particle shape exhibits advantages over nanoparticles in terms of charg ...

Amer Chemical Soc2014

Ultra-Low Thermal Conductivity in Organic-Inorganic Hybrid Perovskite CH3NH3PbI3

László Forró, Richard Gaal, Jacim Jacimovic, Massimo Spina, Endre Horvath, Andrea Pisoni

We report on the temperature dependence of thermal conductivity of single crystalline and polycrystalline organometallic perovskite CH3NH3PbI3. The comparable absolute values and temperature dependence of the two samples' morphologies indicate the minor ro ...

Amer Chemical Soc2014

Functionalized graphene grown by oxidative dehydrogenation chemistry

László Forró, Daniel Oberli, Arnaud Magrez, Arnaud Walter, Jacim Jacimovic, Massimo Spina, Endre Horvath, Laurent Syavoch Bernard

We report on a highly efficient growth of graphene using dehydrogenation of acetylene by an oxidative reaction with carbon dioxide. In few seconds, large-area of copper foil used as catalyst of the reaction is fully covered with graphene. The yield of the ...

Pergamon-Elsevier Science Ltd2014