SnSe has emerged as an efficient thermoelectric material since a high value of the thermoelectric figure of merit ($ZT$) has been reported recently. Here we show with systematic angle resolved photoemission spectroscopy data that the low-lying electronic structures of undoped and hole-doped SnSe crystals exhibit noticeable temperature variation from 80 to 600 K. In particular, the hole effective masses for the two lowest lying valence band maxima are found to be very large and increase with decreasing temperature. Thermoelectric parameters derived from such hole-mass enhancement agree well with the transport values, indicating comprehensively a reduced impact of multivalley transport to the system’s thermoelectric performance.

中文翻译：

---

角度分辨光发射光谱法揭示SnSe中意想不到的大孔有效质量

SnSe已成为一种有效的热电材料，因为它具有很高的热电品质因数（$žŤ$）最近有报道。在这里，我们通过系统角度分辨光发射光谱数据表明，未掺杂和掺杂空穴的SnSe晶体的低洼电子结构在80至600 K范围内表现出明显的温度变化。特别是，两个最低价价带最大值的空穴有效质量被发现非常大，并且随着温度的降低而增加。从这种空穴质量增强得到的热电参数与输运值很好地吻合，表明全面减少了多谷输运对系统热电性能的影响。