Publications de Massimo Spina | EPFL Graph Search

Highly flexible CH3NH3PbI3 micro- and nanowires

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

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

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

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

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, Endre Horvath, Luka Ciric, Bálint Náfrádi, Martial Duchamp, Massimo Spina, 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, Arnaud Magrez, Endre Horvath, Alla Arakcheeva, Richard Gaal, Bálint Náfrádi, Massimo Spina, Jacim Jacimovic, Péter Szirmai, Laurent Syavoch Bernard

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

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

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, Endre Horvath, Massimo Spina

IUCr/Wiley2016

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

László Forró, Massimo Spina, Endre Horvath, Richard Gaal, Bálint Náfrádi, 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