Thermoelectric generator has attracted attention because of their ability to recover waste heat with converting it to electricity. The energy conversion efficiency is related to the thermoelectric figure of merit Z, expressed as Z = S2σ/κ, where σ and κ is electrical and thermal conductivities, respectively, and S is the Seebeck coefficient. Consequently, in order to achieve a high Z value, the material must possess a unique combination of electrical and thermal properties, i.e., metal-like high σ and glass-like low κ. In our previous study on electrical and thermal properties of a Ga-doped Ge0.929Sn0.071 thin film grown on Ge(001), it was revealed that simultaneous realization of a high σ (6.5×102 S/cm) and a low κ (2.0 Wm-1K-1) by the incorporations of the Sn and Ga atoms into Ge matrix [1]. Very recently, Uchida et al. [2] has reported heat transport property of polycrystalline GeSn (poly-GeSn) films on SiO2, together with the carrier transport property, to assess self-heating effect of the poly-GeSn channel thin-film transistors. Here, they showed a relatively lower κ of 5–9 Wm-1K-1 for poly-Ge1-xSnx (x<0.14) compared with that for bulk Ge (60 Wm-1K-1) [3]. These results are quite beneficial in the field of Ge-based thermoelectric generator. However, the thermoelectric properties of GeSn films have not been entirely understood. It is therefore, in the present study, we aim to reveal the thermoelectric properties of the Ge-rich poly-Ge1-xSnx films grown by solid phase crystallization. Doping effects in poly-Ge1-xSnxon the thermoelectric properties will be discussed. Acknowledgments The authors would like to thank Drs. Hiroshi Onoda and Yoshiki Nakashima of Nissin Ion Equipment Co., Ltd. for providing the opportunity to use ion implanters. This work was partially supported by a Grant-in-Aid for Scientific Research (S) (Grant No. 26220605) of the JSPS and PRESTO from JST.