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纯硅由于原材料来源广、熔点高,是潜在的太阳能热发电用热电材料.它的热电绩效因子ZT很小,室温只有0.01.本研究小组通过掺杂和结构纳米化制备了Si_(100)P_(2.5)(GaP)_(1.5),获得813℃时的ZT为0.47.本文在此基础上,通过引入一种新的机制——随机孔洞——来进一步提高纯硅基材料Si_(100)P_(2.5)(GaP)_(1.5)的ZT.结果表明:由于孔洞增加了对低能载流子的过滤,Seebeck系数得到了提高;又由于孔洞对主要携带热量的声子的散射,晶格热导率大大降低,结果Si_(100)P_(2.5)(GaP)_(1.5)的ZT提高了32%.研究结果表明引入随机孔洞是增加纯硅基体系ZT的有效途径.
Pure silicon is a potential thermoelectric material for solar thermal power generation due to its wide source of raw materials and high melting point. Its thermoelectric performance factor ZT is very small, only 0.01 at room temperature. The team prepared Si_ (100) P_ (2.5) (GaP) _ (1.5), and the ZT obtained at 813 ℃ is 0.47.On the basis of this, the introduction of a new mechanism - random holes - to further improve the Si_ (100) P_ (2.5) (GaP) _ (1.5). The results show that the Seebeck coefficient is improved due to the increased filtering of low-energy carriers by the holes, and due to the scattering of holes by phonons that mainly carry heat, The results show that the ZT of Si_ (100) P_ (2.5) (GaP) _ (1.5) is increased by 32% .The results show that the introduction of random holes is an effective way to increase the ZT of pure silicon-based system.