Hybrid Photovoltaic-Piezoelectric Flexible Device for Energy Harvesting from Nature

Abstract

Photovoltaic energy can be expensive if the solar radiation in a particular region is not abundant. When the solar radiation is scarce in a region, there is presence of winds and rainfall. If flexible solar cells are coupled with flexible piezoelectric films then the hybrid structure can generate energy from solar radiation, wind and rainfall. Hybrid piezoelectric-photovoltaic devices have been developed which are capable of generating electricity from solar as well as wind and rain energy. This work focuses on non-transparent hybrid structure which contains copper and aluminium electrodes and eliminates the used of costly indium tin oxide (ITO).These hybrid films are made by depositing organic photovoltaic cell based on P3HT and PCBM on a commercial PVDF film. The hybrid piezoelectric-photovoltaic film was first tested under a solar simulator with 1.5 AM filter at one sun solar intensity. The film produced an open circuit voltage, Voc of 0.43V and a short circuit current density, Isc of 4.48mA/cm2. It was then subjected to a turbulent wind speed of 10m/sec (36km/hour) in a custom built wind tunnel. A peak voltage of 52V was generated by the PVDF substrate due to the oscillations created by the wind. Peak power was also measured using a variable resistor and was recorded to be 85 µW. In order to check if the film was not damaged when it was subjected to the turbulent wind speed, the film was again tested under the solar simulator and did not show any changes in its open circuit voltage or short circuit current.