Έρευνα

Κύρια Πεδία Ερευνητικής Δραστηριότητας του εργαστηρίου Προηγμένων Υλικών και Νανοτεχνολογίας (NAML)

1. Third-generation solar cells (Φωτοβολταϊκά Τρίτης Γενιάς με νανοσύνθετα υλικά)

A) Dye sensitized solar cells (DSSC)

B) Quantum dot sensitized solar cells (QDSSC)

C) Perovskite solar cells (PSC)

The development of 3^rd generation solar cells aims at a high light-to-electricity conversion efficiency with low manufacturing costs, providing additionally some extra unique characteristics that pave the way for a number of alternative and pioneer photovoltaic applications, such as building integration, indoor applications, automotive, wearable electronics, etc. They are fabricated using nanostructures, usually of a mixture of organic and inorganic components.

2. Electrochromic cells (Ηλεκτροχρωμικά Υλικά και διατάξεις- Έξυπνα παράθυρα)

Electrochromic cells are devices that can change their color from transparent to translucent (dark) upon a voltage application. As a result, their transparency, light absorption, reflectance and emission can be controlled. These devices can be used as windows to adjust the incoming sunlight and the heat inside a building, without using shades and blinds, minimizing the heating/cooling loads and at the same time achieving adequate lighting and thermal comfort.

3. Luminescent solar concentrators for light harvesting in c-Si PVs and Glass panes for greenhouses (Συγκεντρωτές Ηλιακής ακτινοβολίας για την ενίσχυση του φωτός σε επιλεγμένες φασματικές περιοχές για την αύξηση της απόδοσης συμβατικών Φωτοβολταϊκών πυριτίου)

Luminescent solar concentrators, also called fluorescent concentrators, consist of a highly transparent matrix, in which luminescent species, mainly organic dye molecules with high extinction coefficient, are dispersed. These dyes absorb incident light and emit it at a red-shifted wavelength, with a high quantum efficiency.

As the luminescent materials emit light in all directions, part of the emitted light is internally reflected at the matrix/air interface. Total internal reflection can effectively trap most of the emitted light and guide it to the edges of the collector. There, it can be transformed into electricity by a solar cell (scheme a).

Alternatively, the luminescent layer can be formed on the upper side of a glass panel following the same principle of light harvesting to the photovoltaic cell (scheme b).

4. Photocatalytic materials for water decontamination and air purification (Φωτοκαταλυτικά Υλικά για τον καθαρισμό νερού και την αποδόμηση ρύπων)

Photocatalysis is a highly efficient treatment to remove recalcitrant dyes and dangerous aromatic materials from water based on the oxidative power of radical species created during exposure to light. Specifically, the reactions include the decomposition of organic compounds into environmental-friendly water and carbon dioxide, leading to interesting properties of surfaces covered with a photocatalyst: self-cleaning, antibacterial and viricidal. Therefore, they are attractive candidates for many environmental applications, such as water purification and waste-water treatment.