Thermoelectric enhancement of p-type Si_(80)Ge_(20) alloy via co-compositing of dual oxides:Respective regulation for power factor and thermal conductivity byβ-Ga_(2)O_(3) and SiO_(2) aerogel powders  

作　　者：Huajun LAI Ying PENG Mengfei WANG Runze SHI Junliang CHEN Chengyan LIU Yifeng WANG Lei MIAO Haiqiao WEI 

机构地区：[1]Key Laboratory of Information Material,Ministry of Education,Guangxi Key Laboratory of Information Material,School of Materials Science and Engineering,Guilin University of Electronic Technology,Guilin 541004,China [2]Guangxi Key Laboratory of Precision Navigation Technology and Application,School of Information and Communication,Guilin University of Electronic Technology,Guilin 541004,China [3]School of Physical Science and Technology,Guangxi University,Nanning 530004,China [4]College of Materials Science and Engineering,Nanjing Tech University,Nanjing 210009,China [5]State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China

出　　处：《Journal of Advanced Ceramics》2023年第2期228-241,共14页先进陶瓷（英文）

基　　金：funded by the National Natural Science Foundation of China (Grant Nos.U21A2054,52061009,52273285,and 52262032);Guangxi Natural Science Foundation of China (Grant No.2020GXNSFAA159111);Guangxi Science and Technology Project (Grant Nos.2021AC19206 and AD20159006);the National Key R&D Program of China (Grant No.2017YFE0198000).

摘　　要：Si-based thermoelectric(TE)materials are exhibiting remarkable perspectives in self-energized applications with their special advantages.However,the relatively high total thermal conductivity(κ)prevents their TE enhancement.Here,a strategy of co-compositing dual oxides was implemented for enhancing the TE properties of p-type Si_(80)Ge_(20) bulks.Composited Ga2O_(3) was demonstrated to enhance the power factor(PF)due to the crystallization-induced effect of produced Ga by decomposition on SiGe matrix.Associating with compositing SiO_(2) aerogel(a-SiO_(2))powder,not only introduced the fine amorphous inclusions and decreased the grain size of host matrix,but also various nano morphologies were formed,i.e.,nano inclusions,precipitations,twin boundaries(TBs),and faults.Combining with the eutectic Ge,hierarchical scattering centers impeded the phonon transport comprehensively(decreasing the phonon group velocity(a v)and relaxation time)for reducing the lattice-induced thermal conductivity(lκ).As a result,a minimumκof 2.38 W·m^(−1)·K^(−1) was achieved,which is significantly dropped by 32.6%in contrast with that of the pristine counterpart.Ultimately,a maximal dimensionless figure of merit(ZT)of 0.9 was achieved at 600℃,which is better than those of most corresponding oxide-composited Si-based bulks.

关 键 词：thermoelectric(TE)materials SiGe Ga_(2)O_(3) SiO_(2)aerogel(a-SiO_(2)) average velocity of sound hierarchical scattering 

分 类 号：TQ135.32[化学工程—无机化工] TB383.1[一般工业技术—材料科学与工程]