Ion migration mediated high Seebeck effect in halide perovskites and application in infrared detection

We present the first-ever study of the ionic thermoelectric properties in typical solid perovskite composition MAPbI3, achieving an extremely high Seebeck coefficient of 35.7 mV/K and revealing its mechanism. This remarkable Seebeck effect is applied in infrared detection, where carbon/MAPbI3 single crystal/carbon photo-thermoelectric detectors exhibit high response (0.58 V/W) and produce well-solved imaging results. [Display omitted] •The first-ever study of ionic thermoelectric properties in MAPbI3 perovskite is presented.•An extremely high Seebeck coefficient of 35.7 mV/K in MAPbI3 thin films has been achieved.•We have clearly revealed the internal mechanism that produces such a large Seebeck coefficient.•A sensitive photo thermoelectric detector based on carbon/MAPbI3/carbon is acquired. Thermoelectric materials play an important role in thermopower systems, thermal sensing and infrared photo-thermoelectric imaging. Ionic thermoelectric materials have recently attracted attentions considering their relatively high Seebeck coefficient. However, the ionic thermoelectric materials have to use liquid or hydrogels for ion conduction, and are susceptible to leakage, evaporation and portability issues. Metal halide perovskites possess low thermal conductivity and prominent ion migration characteristics, making them theoretically suitable candidates for thermoelectric conversion. Here we present the first-ever study of the ionic thermoelectric properties in typical solid perovskite composition MAPbI3, revealing an extremely high Seebeck coefficient of 35.7 mV/K. Furthermore, the assembled photo-thermoelectric detector of carbon/MAPbI3 single crystal/carbon demonstrated a high response (0.58 V/W) toward infrared light and the imaging test was well resolved. This research provides a novel avenue to investigate efficient thermoelectric devices based on ionic and electronic mixed conductors and develop photo-thermoelectric applications.