Thermoelectric(TE)materials can di-rectly exchange heat and electricity in the solid state.TE devices that do not contain moving parts or produce emis-sions have been commercialized as elec-tronic coolers and temperature stabiliz-ers,such as refrigerators,wine cellars,portable coolers and temperature con-trollers for optical communication equip-ment,infrared sensors and high-powered lasers.TE cooling is suitable for both lo-calized and active cooling and may be the only viable solution to heat manage-ment challenges that restrict the devel-opment of next-generation communica-tion and computer technologies.In the last few decades,increasing attention has been paid to TE technology because of its ability to harvest and convert waste heat into electricity,leading to the effi-cient use of energy.Furthermore,minia-turized TE power generators can be used in portable and/or self-powered energy sources[1],including wearable electron-ics[2]and the Internet of things(IoT)systems[3].