The IMPRESSIVE global objective will be achieved though the completion of 7 clear, measurable, realistic and achievable Specific Objectives (SO):


Absorb light only in the UV part (<450nm) and the NIR part (>700nm) of the solar spectrum.

Nowadays, most PV technologies absorb the visible domain of the light spectrum that is why these devices are not transparent or no less than semi-transparent. The opsin and rhodopsin receptors composing the three types of cones of retina are most sensitive at 555nm in daylight and shifts to 500nm when light gets to shadow.

To reach the target of transparency to human eyes, IMPRESSIVE project will focus on the development and integration of efficient UV absorber based on perovskite solar cell (λ < 450 nm) and Near-Infrared (NIR) absorber based on dye- sensitised solar cell (λ > 700 nm) to offer an unique fully transparent and colourless PV tandem display. These activities are at the core of WP2 and WP3, respectively. The Average Visible Transmission (AVT) is targeted above 55%.


Average Visible Transmission targeted


Development of transparent hole and electron transporting layers or electrolytes adapted to UV-perovskite solar cell and NIR-dye sensitised solar cells, respectively

Transparent charge transport layers are required for the UV-perovskite solar cell on the one hand and liquid electrolyte including a colourless one electron redox mediator for the NIR-dye sensitised solar cell on the other hand. IMPRESSIVE will work on this specific objective in WP2 and in WP3, respectively.


Development of transparent high performance counter-electrode using graphene technology and high transparent conductive oxides

Graphene and related 2D materials (GRM) will be employed to improve the electrocatalytic properties of the counter-electrode with respect to the redox mediators developed in WP3 and to provide also higher transparency than the benchmark platinised counter-electrode.

A graphene-based electrode with an electro-catalytic activity greater than Pt will be demonstrated and applied to the fabrication of the NIR cell. This will be done in WP3. At the same time, in WP2, transparent electrodes will be achieved by high conductive transparent oxides (such as FTO, ITO, AZO etc.) already deposited on glass or sputtered by project partners.


Reach up to 14% of tandem cells’ efficiency and 25 years lifetime

The Power Conversion Efficiency is expected to reach 14% under standard A.M. 1.5G conditions through the combination of a NIR-DSSC that should achieve PCE of at least 8% and the UV-PSC device to reach 6% PCE.

The PV cells should also be stable for more than 25 years complying with IEC61646 (PCE > 80% of the initial value). Reaching this target of both efficiency and life-in service is the aim of WP6.


Years of stability


Demonstrate the realisation of a window at industrial level (module scale)

IMPRESSIVE will demonstrate the realisation of a fully transparent PV cell on a large scale. This will be done following 3 steps, carried on in WP6.


Steps for transparency:

– Large surface single cell (10 × 150 mm)

– A module (150 × 150 mm)

-Large area module (200 × 300 mm)


Ensure the market uptake of the IMPRESSIVE innovative technology

A major priority of the IMPRESSIVE project is to ensure a strong and fast market uptake of the solution developed. The industrial HG is directly involved in the project to ensure the industrialisation of the process and the commercialisation of the solution in the years following the project. Moreover, communication on the project and dissemination of the results will be done in WP8 and associated with a strong exploitation strategy elaborated in T1.3.


Run a complete LCA and LCC of the final product

A detailed Life Cycle Assessment (LCA) will be done during the project to calculate the impact of the solution on different aspects of the environment. Associated to it, a Life Cycle Cost (LCC) will also be performed to see the structure of costs and propose ways to optimise it as well as next steps in a roadmap.