Project NANOPTO

H2020-MSCA-IF-2015-703018


Novel processing of colloidal nanocrystals for optoelectronic applications

NANOPTO is a Marie Skłodowska-Curie actions Individual Fellowship that aims at developing novel physicochemical routes to obtain a semiconductor matrix embedding dispersed quantum-dots starting from colloidal nanocrystals. In recent years, a multitude of different semiconductor materials have been synthesized and studied to increase the performance of current technologies or to develop new and attractive applications. As a first-order approximation, materials boosting high photoluminescence quantum yield possess low or hindered charge mobility as, for example, pristine colloidal semiconductor nanocrystals (NCs). To overcome this limitation, many different NC processing techniques have been developed, but all of them either cause the formation of charge trap-states on the NC surface (thus quenching the photoluminescence) or do not significantly enhance the charge mobility. For this reason, NANOPTO will tackle this fundamental limitation of NCs by developing novel general methods to enhance their charge mobility without creating surface trap-states, thus leading the way to the development of more efficient light-emitting diodes (LEDs) and solar cells that can be processed in solution. In particular, NANOPTO aims at exploiting both chemical and physical routes to prepare colloidal NCs and solder them in solid-state thus creating a bulk semiconductor matrix (granting enhance charge mobility) embedding quantum-dots (granting the desired optical properties).

Colloidal NCs are becoming more and more popular in a wide range of applications thank to their versatile chemical synthesis, which allows their optical properties to be tailored by controlling their size, shape and composition. Due to their small size (typically from few to tens of nanometers) and the high surface to volume ratio, NCs electronics properties are deeply affected by their surface, which is typically covered with organic ligands. The ligands are left on the surface during the synthesis and they are responsible to stabilize the colloidal NCs in the solvent. Furthermore, ligands play a dominant role in determining the interface between two or more neighbouring NCs in the solid state, thus strongly inhibiting electrical charge injection and mobility. To solve this issue, many different ligand removal and replacement reactions (commonly referred to as ligand-exchange) have been developed to try to improve electrical charge mobility of NCs. Yet, most ligand-exchange reactions have a detrimental effect on the photophysical properties of NCs, i.e. these reactions damage the NCs surface inducing photoluminescence quenching. NANOPTO proposes two possible venues to solve this issue via novel physicochemical routes.


The project runs from September 2016 to September 2018 and is carried out by Dr. Francesco Di Stasio under the supervision of Prof. Gerasimos Konstantatos at the Institute of Photonic Sciences (ICFO) in Castelldefels (Barcelona)