In this study, Si2N2O films were prepared from a Si2N2O suspension via pulsed electrophoretic deposition. The resulting Si2N2O electrophoretically deposited films were sintered by applying laser irradiation at a wavelength of 460 nm. Laser sintering caused the film to shrink by approximately 60% in the direction normal to the substrate. The cooling capacity of the laser-sintered film was approximately 1.5 times higher than that of the electrophoretically deposited film, and the temperature of the former was 1.2 °C lower than that of a reference device at an ambient temperature of 90 °C. The relative permittivity of the laser-sintered Si2N2O film was in the range of 7–8, indicating its potential application to the development of low-k radiative cooling devices. We fabricated a device that combined a laser-sintered Si2N2O film with a Peltier element. This device was observed to have an electromotive force of 0.286–0.727 mV in an ambient temperature range of 30–90 °C. The thermoelectromotive force generated by this composite device suggests the possibility of passive power generation.