Si-based thermoelectric device with cavity achieving a normalized power output of 43 μW cm −2 K −2

Abstract A remarkable thermoelectric (TE) power output of 43 μW cm −2 K −2 has been recorded by a silicon (Si) based integrated TE device fabricated by using standard complementary metal-oxide semiconductor technology. The TE device comprised micrometer-scale Si sheets suspended over a cavity formed on a Si substrate. The power-generation performance was investigated as a function of the Si sheet length and cavity width. The evaluation of the fabricated devices revealed a strong correlation between the optimal cavity size and Si sheet length in relation to the power generation performance. Through optimal design, a TE device with a 15 μm cavities and 5 μm Si-sheet achieved a normalized power output of 43 μW cm −2 K −2 . This result opens a pathway for mass-producible, high-efficiency thermal energy harvesting.