Singapore
Ming Hui Chua Institute of Materials Research and Engineering (IMRE) Agency for Science, Research and Technology (A*STAR) Singapore Singapore
Minzhi Du Key Laboratory of Textile Science & Technology of Ministry of Education College of Textiles Donghua University Shanghai China
Zeng Fan School of Physics Dalian University of Technology Dalian P. R. China
Xue Han Key Laboratory of Textile Science & Technology of Ministry of Education College of Textiles Donghua University Shanghai China
Lin Hu China‐Australia Institute for Advanced Materials and Manufacturing Jiaxing University Jiaxing P. R. China
Fengxing Jiang Flexible Electronics Innovation Institute Jiangxi Science and Technology Normal University Nanchang P. R. China Department of Physics Jiangxi Science and Technology Normal University Nanchang P. R. China
Yuanyuan Jing Key Laboratory of Textile Science & Technology of Ministry of Education College of Textiles Donghua University Shanghai China
Meng Li MOE Key Laboratory of Low‐grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory School of Energy & Power Engineering Chongqing University Chongqing P. R. China
Zaifang Li China‐Australia Institute for Advanced Materials and Manufacturing Jiaxing University Jiaxing P. R. China
Peipei Liu Department of Physics Jiangxi Science and Technology Normal University Nanchang P. R. China
Congcong Liu Flexible Electronics Innovation Institute Jiangxi Science and Technology Normal University Nanchang P. R. China
Yang Liu MOE Key Laboratory of Low‐grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory School of Energy & Power Engineering Chongqing University Chongqing P. R. China
Baoyang Lu Flexible Electronics Innovation Institute Jiangxi Science and Technology Normal University Nanchang P. R. China
Chunhong Lu Key Laboratory of Textile Science & Technology of Ministry of Education College of Textiles Donghua University Shanghai China
Jianyong Ouyang Department of Materials Science and Engineering National University of Singapore Singapore Singapore
Lujun Pan School of Physics Dalian University of Technology Dalian P. R. China
Yue Shu MOE Key Laboratory of Low‐grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory School of Energy & Power Engineering Chongqing University Chongqing P. R. China
Kuan Sun MOE Key Laboratory of Low‐grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory School of Energy & Power Engineering Chongqing University Chongqing P. R. China
Ady Suwardi Institute of Materials Research and Engineering (IMRE) Agency for Science, Research and Technology (A*STAR) Singapore Singapore
Zhenghong Xiong MOE Key Laboratory of Low‐grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory School of Energy & Power Engineering Chongqing University Chongqing P. R. China
Jianwei Xu Institute of Materials Research and Engineering (IMRE) Agency for Science, Research and Technology (A*STAR) Singapore Singapore
Jingkun Xu Flexible Electronics Innovation Institute Jiangxi Science and Technology Normal University Nanchang P. R. China
Yuanyuan Zheng Key Laboratory of Textile Science & Technology of Ministry of Education College of Textiles, Donghua University Shanghai China
Yujie Zheng School of Energy & Power Engineering State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing P. R. China
Fengling Zhang Department of Physics Chemistry and Biology Linköping University Linköping, Sweden
Kun Zhang Key Laboratory of Textile Science & Technology of Ministry of Education College of Textiles Donghua University Shanghai China
Yinhua Zhou Wuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan Hubei China
Yongli Zhou MOE Key Laboratory of Low‐grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory School of Energy & Power Engineering Chongqing University Chongqing P. R. China
Preface
Thermoelectric materials are interesting because they can be used to directly convert heat into electricity. Some conductive materials can exhibit a notable voltage under temperature gradient, that is, the Seebeck effect. The thermovoltage with respect to the temperature is called Seebeck voltage. The Seebeck voltage can be positive or negative depending on the accumulation of the charge carrier(s) at the two ends under temperature gradient. A p‐type thermoelectric material exhibits a positive Seebeck voltage, while an n‐type thermoelectric material has a negative Seebeck voltage. High Seebeck coefficient has been observed on semiconductors and semimetals. The value is related to the relative position of the Fermi level from the top of the valence band or the bottom of the conduction band or simply the doping level since a change in the doping level can shift the Fermi level. Apart from the Seebeck coefficient, a high electrical conductivity is also required for efficient thermoelectric conversion. However, a good thermoelectric material should have a low thermal conductivity so that more heat can be utilized for power generation. Thermoelectric materials are used as the active materials of thermoelectric generators. They can be used in thermoelectric cooling systems in terms of the Peltier effect as well.
The conventional thermoelectric materials are inorganic semiconductors or semimetals such as Bi2Te3 and its derivatives or analogues. These materials can exhibit high Seebeck coefficient and high electrical conductivity, but they also have a problem of high thermal conductivity. Hence, great effort has been made on lowering the thermal conductivity of inorganic thermoelectric materials besides on the improvement in the Seebeck coefficient and/or electrical conductivity. Consider for practical application, inorganic thermoelectric materials are usually brittle, and thus they are not suitable for flexible thermoelectric systems.
Polymers emerge as the next‐generation thermoelectric materials mainly due to their high mechanical flexibility. Flexible thermoelectric materials can enable the realization of flexible or even portable/wearable thermoelectric generators or coolers. They are significant because of the ubiquitous heat on earth and the convenient heat collection related to the mechanical flexibility. For example, a wearable thermoelectric generator can harvest heat from human body and provide electricity to other wearable or implanted devices that are used for communication or healthcare. Polymers have much
