New frontier in printed thermoelectrics: formation of β-Ag2Se through thermally stimulated dissociative adsorption leads to highZT

Printed thermoelectrics (TE) could significantly reduce the production cost of energy harvesting devices by large-scale manufacturing. However, developing a high performance printable TE material is a substantial challenge. In this work, a new one-pot synthesis and processing of high performance Ag2Se based n-type printed TE materials is reported. Structural analyses reveal that orthorhombic beta-Ag2Se is the dominant phase in the n-type printed material compounds. For a printed material at room temperature, a breakthrough power-factor of similar to 17 mu W cm(-1)K(-2)with a record high figure-of-meritZT similar to 1.03 is achieved. A high averageZT, an important parameter for device applications, of similar to 0.85-0.60 has been realized in the temperature range of 300 K to 400 K. Using this material for n-type legs in combination with commercially available PEDOT:PSS for p-type legs, a printed TE generator (print-TEG) of two thermocouples has been fabricated. An output voltage of 17.6 mV and a high maximum power outputP(max)of 0.19 mu W are achieved using the print-TEG at Delta T= 75 K.