笼状热电材料p型和n型Ba8Ga16Ge30单晶之间载流子的调谐研究

Study on Carrier Tuning between p- and n-Ba8Ga16Ge30 Single Crystals

摘要:

本研究首次实现了p型和n型Ba8Ga16Ge30 (BGG)单晶之间载流子类型的相互转换.采用以对方单晶为前驱体的再合成调制方法，再次制备了Ba8Ga16Ge30 (BGG)单晶笼状热电材料，利用物理属性测量系统(PPMS)测量单晶样品的变温电阻率并对其载流子类型进行了评价. 结果表明：p型和n型Ba8Ga16Ge30 (BGG)单晶之间载流子类型可以成功地进行相互转换，且n型转换为p型样品时前驱体状态及成分配比的不同可导致改性后样品电阻率及载流子浓度不同. 以单晶为前驱体的晶体再生长以及载流子调节对于制备珍贵同位素替代的大块单晶具有指导意义，有益于材料内部笼内及笼上原子的非简谐振动研究，并对热电材料的再生利用也具有重要意义.

Abstract:

Carrier-type conversion between p- and n-Ba8Ga16Ge30 (BGG) single crystals was realized. The temperature dependence of resistivity has been measured to judge the carrier types of the new batch samples synthesized using physical property measurement system (PPMS). The resistivity data show that p- and n-type BGG could be converted to each other under the addition of excessive components. This approach is instructive for tuning the charge carrier type or concentration to effectively investigate the vibration behavior of guest atoms and host cages. In addition, it can also provide some important information to the recycle of the thermoelectric materials.