Department of Physical Science and Technologies of Matter (DSFTM) @ the Italian National Research Council (CNR)

DSFTM has 11 Institutes and 41 branches in 15 regions, for a total of 1.200 staff members and far more students involved. DSFTM mission is to perform research in its own Institutes, to promote innovation and competitiveness of the national/international industrial system.

Piazzale Aldo Moro 7, 00185 Rome

BioPhotovoltaics: Natural pigments in dye-sensitized solar cells (CNR 10056)

managed by DSFTM


Dye-sensitized solar cells (DSSCs) which are also called Graetzel cells are novel type of solar cells. The technology and devices proposed relates to a photo-electrochemical solar cell comprising a photoanode made of a semiconductor-based nanocrystalline film with a natural pigments as photosensitizer (i.e. anthocyanin and/or betalain dye or an engineered mixture of both) adsorbed on it and deposited on a transparent and conductive support. A wide band gap semiconductor like TiO2 is used for charge separation and transport. The cathode, besides the conventional ones, can be constructed by glass or metal, such as ceramic, bricks, tiles, wood, and fabrics, all suitably made conductive and coated with catalyst.
The dye extraction methods, the choice of the right mixtures of natural pigments have been characterized and studied in order to reach stability and electrical efficiency comparable with dyes based on metal complexes.


The Bio-photovoltaics cell proposed provides reasonable light harvesting efficiency, sustainability, low cost and easy waste management. Its main advantages are mainly low cost production, flexibility, performance also at diffuse light and multicolor options.
The cell could be integrated into large varieties of products, e.g. hand bags or clothing, indoor applications, and building-integrated photovoltaics such as roll-able devices for walls of buildings or windows. But components of a DSSC should be optimized for the suitable applications.


The photoelectric performances of the natural DSSCs sensitized cells have been compared to a standard artificial dye based on a Ruthenium dicarboxylic polypyridine complex (referred to as the artificial complex N3) under similar conditions. The results achieved shows that our natural cells present an efficiency of 70% with respect to the artificial one (i.e 1.5%).


Solar cells are devices designed to convert solar energy into electricity. In particular the photo-electrochemical cells, named as third-generation solar cells, offer the possibility to move from the dependence of silicon and, thanks to the use of natural dyes and other cheap components, makes them a more economical viable strategy with respect to first generation solar cells (Silicon-based). The possible application spans from the integration of the cell into in floor or wall tiles, furniture, toys, cars, railway carriages, clothes and garments in general, sails, tents, beach umbrellas, etc.
Moreover, since the bio-photovoltaic cell is composed by natural pigments and material that present an easy and safety waste management, the technology can be exploited in the educational market by building kits for the dissemination of renewable energy culture.

Readiness Level (TRL)

technology validated in lab
"Development of new materials, to improve the photoelectric performance of the devices."
(The pie chart refers to the entire portfolio contained in the database of the helpdesk)

Technology Readiness Levels (TRL) are a method of estimating technology maturity of Critical Technology Elements (CTE) of a program during the acquisition process. The use of TRLs enables consistent, uniform, discussions of technical maturity across different types of technology.

Patent Grading Report

Patent Grading Report

The Grading Patents Report evaluates and grades US patents

Sample Buy from Wisdomain


Current status

US9218914 (B2), US8748738 (B2), EP2342725 (A1)


Available for

Licensing and Assignment


Giuseppe Calogero, Gaetano Di Marco


Case manager: Giulio Bollino

EU-Japan Centre
European CommissionMeti