通过超快烧结法制备高性能硒化银热电材料

Preparation of High-performance Silver Selenide Thermoelectric Materials by an Ultrafast Sintering Method

Ag_(2)Se是一种本征热电性能和机械性能良好的n型室温热电材料,近年来受到研究者的广泛关注。本文将冷压工艺和碳热法相结合开发了一种超快烧结法来制备Ag_(2)Se块体材料,可在1 min内完成烧结。通过调整烧结温度,Ag_(2)Se样品的电输运性能可以得到调控,而超快烧工艺能够获得多孔样品,使热导率显著降低,在300 K时,超快烧结样品的总热导率能低至0.56 W/(m·K),相比于放电等离子体烧结法制备的纯相Ag_(2)Se块体,降低了约44%。最终在673 K温度下烧结的Ag_(2)Se样品获得了约为0.66的室温zT值,与传统方法制备的室温热电材料相当。本工作展示了一种便捷、高效的热电材料烧结方法,可以制备出热电性能优异的Ag_(2)Se块体,同时为Ag_(2)Se进一步的性能优化提供了基础。

Ag_(2)Se is an n-type room temperature thermoelectric material with excellent intrinsic thermoelectric and mechanical properties and has received increasing attention from researchers in recent years.In this study,we have developed an ultrafast sintering method to prepare Ag_(2)Se bulk materials combining the cold pressing process and the Joule-heating method,which can be completed in less than one minute.By modifying the sintering temperature,the electrical transport properties of the Ag_(2)Se samples can be tuned.The ultrafast sintering process maintains the porous structure of the cold pressed samples,resulting in a significantly reduced thermal conductivity as low as 0.56 W/(m·K)at 300 K,which is~44%lower than that of the Ag_(2)Se bulk prepared by using the spark plasma sintering method.Eventually,a room-temperature zT value of~0.66 is obtained in ultrafastsintered Ag_(2)Se at 673 K,which is comparable to the room-temperature thermoelectric materials prepared by conventional methods.This work proposes a convenient and efficient method for sintering thermoelectric materials with promising thermoelectric performance.