講演情報
[17a-P01-23]Boosting p-Type Thermoelectric Performance in Epitaxial Mg2Sn Thin Films with Li Doping
〇(DC)Kenneth Magallon Senados1,2, Takashi Aizawa2, Isao Ohkubo2, Takeaki Sakurai1, Takao Mori1,2 (1.Tsukuba Univ., 2.NIMS)
キーワード：
thermoelectrics、thin films、epitaxial
Thin-film materials like Mg2Sn are promising for thermoelectric (TE) devices in IoT applications due to their cost-effectiveness and scalability. However, p-type Mg2Sn faces challenges such as low carrier concentration and less favorable band structures compared to n-type counterparts. This study investigates Li as a p-type dopant, capitalizing on its low formation energy at the Mg site. Mg2-xLixSn films were grown via molecular beam epitaxy (MBE) on sapphire substrates. X-ray diffraction (XRD) revealed Mg2Sn phases and secondary Sn phases at higher Li concentrations due to stoichiometric imbalance and phase destabilization.Thermoelectric measurements showed a peak power factor of 2.86 × 10-3 W/m·K at 450 K for Mg1.95Li0.05Sn. Higher Li content introduced defects and reduced performance, which was mitigated by post-growth annealing. Annealing improved Seebeck behavior, reduced defects, and enhanced carrier mobility, highlighting the potential of Li-doped Mg2Sn films for p-type TE applications.