Development of new materials with high thermoelectric coefficient will expand the capability of thermoelectric sensors. In this work, we investigate the thermoelectric properties of silicon carbide (SiC) on silicon (Si) heterojunction towards self-powered temperature sensing applications. A SiC/Si heterojunction device was designed and fabricated to measure the Seebeck coefficient. The device showed a high Seebeck coefficient of -156.11 V at 336 K, which progressively increased with increasing temperature and reached -374.78 V at 383 K. These thermoelectric characteristics indicate superior result compared to previous polycrystalline and monocrystalline SiC thin films. The innovative heterojunction demonstrated in this work holds promises for developing highly sensitive self-powered thermal sensors.