The urgent goals of achieving carbon neutrality and securing sustainable energy sources have triggered the search for innovative and economically attractive means of harnessing solar energy. Photo-thermal-electric (PTE) conversion is an effective strategy for harvesting solar energy and converting it into electricity. This technique combines photo-thermal and thermoelectric effects, whereby the temperature difference induced by the absorbed solar radiation is converted to electric voltage based on the Seebeck effect. Wavelength-selective absorption film is designed to allow visible light to pass through while absorbing as much ultraviolet (UV) light and near infrared (NIR) light as possible and converting them into heat. Thus, heat is collected continuously and then laterally conducted through the film to the hot side of thermoelectric devices. This power-generating system decouples the energy conversion efficiency from light transparency of the window, thus enabling independent regulation for both.