Enhanced photodetector at low-temperature via thermo-phototronic effect in N-type SnSe:Br single crystal

Self-powered photodetectors play an important role in building passive monitoring networks and interactive intelligent platforms. However, when low-temperature, the degradation of performance always plagues the development of photovoltaic-based photodetectors, especially in the adaptation of photovoltaic conversion technology to environmental diversification. We adopt an emerging bromine doped n-type SnSe thermoelectric single crystal as a core element with Ag/SnSe:Br/ITO structure to achieve the low-temperature enhanced photoelectric performance, which originates from the thermo-phototronic effect of thermoelectric materials. When the temperature drops from 300 K to 100 K, the response current and voltage of Ag/SnSe:Br/ITO device increase by 139% and 696%, respectively. In addition, the responsivity and specific detectivity of the device at 100 K are 7.95 and 2.74 times higher than those at 300 K, respectively, which enhanced output performance at low-temperature may be related to the acceleration of photogenerated electrons caused by the driving force of the thermoelectric effect. This work provides a simple structure, low-temperature enhanced photodetectors.