Photonic enhanced flexible photothermoelectric generator using MXene coated fullerenes modified PEDOT:PSS films for solar energy harvesting

Photothermoelectric conversion technology from light and heat into electricity has been proved to be an effective method and associated with photothermal and thermoelectric (TE) effects. Wherein, there are great challenges in the structural design that the cold and hot side distribution in planar structure limits the selection of materials to obtain the high output voltage. Here, the half-vertical heterojunction structure of the photothermoelectric generator (PTEG) is adopted for enhanced performance to realize effective energy utilization. The PTEG is constituted by the MXene half-coated fullerenes-modified PEDOT:PSS to obtain wide spectral response. The output voltage of the prepared PTEG can be stabilized at 2.15 mV under the irradiation of a laser wavelength 808 nm with power of 25 mW. Under simulated sunlight irradiation, with the assistant of fullerenes, the output voltage was improved by 43.83 % from 146 to 210μ V. Furthermore, the voltage can be enhanced by TE voltage increasement via temperature gradient, and the 66.19 % increment of output voltage is evaluated from 210 to 349 μV. In addition, PTEG has also excellent electrothermal effect, which was applied into detecting whether the battery is fully charged via adhering to thermal sensitive materials. By means of half-vertical heterojunction structure to the PTEG, a new choice for the PTEG is provided to make better use of sunlight.