Thermoelectric properties and morphology of Si-Ge-Au amorphous thin films with superior performance at near room temperature

Necessary conditions for superior thermoelectric power of Si/Au artificial superlattice thin-film

“…A conventional DC method and a conventional DC four-terminal method were employed for the measurements of thermoelectric power and electrical resistivity (parallel to the layers), respectively. [13][14][15][16][17][18][19][20][21][22][23][24] The samples were H-shaped, similarly to those in previous studies. [13][14][15][16][17][18][19][20][21][22][23][24] The thermoelectric power was measured with a temperature difference (ΔT) of at least ΔT > 5 K.…”

“…[13][14][15][16][17][18][19][20][21][22][23][24] The samples were H-shaped, similarly to those in previous studies. [13][14][15][16][17][18][19][20][21][22][23][24] The thermoelectric power was measured with a temperature difference (ΔT) of at least ΔT > 5 K.…”

“…The samples were prepared in an ultrahigh-vacuum evaporation system, as used previously. [13][14][15][16][17][18][19][20][21][22][23][24] The sample preparation system had three evaporation sources, which employed three electron beam guns: Au, Ge, and Si. In this study, two of the three evaporation systems were used.…”

“…[2][3][4][5][6][7][8][9][10][11] A Si-Ge-Au superlattice thin-film has the highest performance among the thermoelectric materials. [12][13][14][15][16][17][18][19][20][21][22][23][24] However, the reproducibility of this material is very low. The authors have made more than 800 samples, but only around 10 samples showed excellent performance (absolute value of thermoelectric power |α| > 10 −3 V•K −1 ).…”

“…Therefore, the origin of the superior thermoelectric performance was not the superlattice structure. 14,20) At the early stage of this research, the authors postulated the existence of an unknown amorphous phase that was responsible for the superior thermoelectric power.…”