16 March 2018
In this paper, a new way of preparing semi-transparent solar cells using Cu(In 1−xGa x)Se 2 (CIGS) chalcopyrite semiconductors as absorbers for BIPV applications is presented. The key to the elaboration process consists in the co-electrodeposition of Cu-In-Ga mixed oxides on submillimetric hole-patterned molybdenum substrate, followed by thermal reduction to metallic alloys and selenisation. This method has the advantage of being a selective deposition technique where the thin film growth is carried out only on Mo covered areas. Thus, after annealing, the transparency of the sample is always preserved, allowing light to pass through the device. A complete device (5 × 5 cm 2) with 535 μm diameter holes and total glass aperture of around 35% shows an open circuit voltage (V OC) of 400 mV. Locally, the I-V curves reveal a maximum efficiency of 7.7%, V OC of 460 mV, J SC of 24 mA.cm −2 in an area of 0.1 cm 2 with 35% aperture. This efficiency on the semi-transparent area is equivalent to a record efficiency of 11.9% by taking into account only the effective area.