Silicon-based hybrid cell for harvesting solar energy and raindrop electrostatic energy

Abstract Silicon-based solar cell is by far the most established solar cell technology. The surface of a Si solar cell is usually covered by a layer of transparent material to protect the device from environmental damages/corrosions. Here, we replaced this protection layer by a transparent triboelectric nanogeneartor (TENG), for simultaneously or individually harvesting solar and raindrop energy when either or both of them are available in our living environment. The TENG is made of a specially processed polytetrafluoroethylene (PTFE) film, an indium tin oxide (ITO) and a polyethylene terephthalate (PET) layer. Under solar light irradiation (12 W/m 2 ) in a rainy day, the fabricated high-efficiency solar cell provides an open-circuit ( V oc ) of 0.43 V and short-circuit current density ( J sc ) of 4.2 A/m 2 . And the TENG designed for collection of raindrop energy gives an AC V oc of 30 V and J sc of 4.2 mA/m 2 when impacted by water drops at a dripping rate of 0.116 ml/s. In rainy days, the performance of solar cell decreased greatly, while TENG can be a good compensation as for green energy harvesting. From these results, we can see that the hybrid cell formed by a solar cell and a water-drop TENG have great potential for simultaneously/individually harvesting both solar energy and raindrop electrostatic energy under different weather conditions, especially in raining season.