SnSe single crystals have been demonstrated to possess excellent thermoelectric properties.In this work,we demonstrate a grain size control method in growing nanocrystalline SnSe thin films through a glancing angle pu...SnSe single crystals have been demonstrated to possess excellent thermoelectric properties.In this work,we demonstrate a grain size control method in growing nanocrystalline SnSe thin films through a glancing angle pulsed-laser deposition approach.Structural characterization reveals that the SnSe film deposited at a normal angle has a preferred orientation along a axis,while by contrast,the SnSe film deposited at an 80glancing angle develops a nanopillar structure with the growth direction towards the incident atomic flux.The glancing angle deposition greatly reduces the grain size of the thin film due to a shadowing effect to the adatoms,resulting in significantly increased power factor for more than 100%.The maximum Seebeck coefficient and power factor are 498.5 mV=K and 18.5 mWcm^(-1)K^(-2),respectively.The enhancement of thermoelectric property can be attributed to the potential barrier scattering at grain boundaries owing to the reduced grain size and increased grain boundaries in the film.Given this enhanced power factor,and considering the fact that the nanopillar structure should have much lower thermal conductivity than a plain film,the zT value of such made SnSe film could be significantly larger than the corresponding single crystal film,making it a good candidate for thin film-based thermoelectric device.展开更多
Achieving high thermoelectric pe rformance in thin fiIm heterostructures is essental for integrated and minlatured ther moelectric device applcations.In this work,we d emonstrate a mechansm and device performance of e...Achieving high thermoelectric pe rformance in thin fiIm heterostructures is essental for integrated and minlatured ther moelectric device applcations.In this work,we d emonstrate a mechansm and device performance of enh anced themoelectnic perfomance induced by interfuclal effect in a tansitdon metal dichalcogenides SrTiO_(3)(STO)heterpstructure Owing to the fomed conductive interface and elevated conductivity.the ZrTe_(2)/STO he teras tructure presents large thermoelectric power factor of 3.7×10^(5)μWcm^(-1)K^(-2) at 10 K.Fomat ion of quasi-wo dimensional conductance at the interface s atributed for the lage Seebeck coffcent and high electnical conductivity leading to high thermoelectric perfor mance which is demonstrated by a prototype device attaining 3 K cooling with 100 mA current input to this heterostructure This supenior themoelectnic property makes this he teros tructure a promtsing candidate for future thermoelectric device.展开更多
Bi_(0.85)La_(0.15)FeO_(3)(BLFO)nanotubes with an average diameter of about 200 nm and wall thickness of about 20 nm are fabricated by solgel alumina template technique,and their room-temperature multiferroic properti...Bi_(0.85)La_(0.15)FeO_(3)(BLFO)nanotubes with an average diameter of about 200 nm and wall thickness of about 20 nm are fabricated by solgel alumina template technique,and their room-temperature multiferroic properties are studied.Piezoelectricity and ferroelectricity in the BLFO nanotubes are revealed by piezoresponse force microscopy study of individual nanotube.Doping the BiFeO_(3)nanotubes with La reduces the crystallization temperature and results in a reduced lose of Bi and therefore improved multiferroic properties of the nanotubes.Enhanced weak ferromagnetism is also observed,and it is attributed to the nano-crystalline structure of the nanotubes.展开更多
基金supported by the National Natural Science Foundation of China(62174059,51872099,and 91963102)Hong Kong Research Grant Council(15300619)+3 种基金Science and Technology Program of Guangzhou(201905-0001)Guangdong Science and Technology ProjectInternational Cooperation(2021A0505030064)the Program for Chang Jiang Scholars and Innovative Research Teams in Universities(IRT_17R40)the 111 Project。
基金supported by the National Natural Science Foundation of China(62174059,52250281 and 91963102)the Hong Kong Research Grant Council(15300619)+3 种基金the Science and Technology Projects in Guangzhou(202201000008)Guangdong Science and Technology Project-International Cooperation(2021A0505030064)Guangdong Provincial Key Laboratory of Optical Information Materials and Technology(2017B030301007)the Joint Funds of Basic and Applied Basic Research Foundation of Guangdong Province(2019A1515110605)。
基金We thank support from The Hong Kong Polytechnic University(Grant Nos.1-ZVCG,1eZVGH,4eZZDC,and DD7F).
文摘SnSe single crystals have been demonstrated to possess excellent thermoelectric properties.In this work,we demonstrate a grain size control method in growing nanocrystalline SnSe thin films through a glancing angle pulsed-laser deposition approach.Structural characterization reveals that the SnSe film deposited at a normal angle has a preferred orientation along a axis,while by contrast,the SnSe film deposited at an 80glancing angle develops a nanopillar structure with the growth direction towards the incident atomic flux.The glancing angle deposition greatly reduces the grain size of the thin film due to a shadowing effect to the adatoms,resulting in significantly increased power factor for more than 100%.The maximum Seebeck coefficient and power factor are 498.5 mV=K and 18.5 mWcm^(-1)K^(-2),respectively.The enhancement of thermoelectric property can be attributed to the potential barrier scattering at grain boundaries owing to the reduced grain size and increased grain boundaries in the film.Given this enhanced power factor,and considering the fact that the nanopillar structure should have much lower thermal conductivity than a plain film,the zT value of such made SnSe film could be significantly larger than the corresponding single crystal film,making it a good candidate for thin film-based thermoelectric device.
基金We thank support from Guangdong-Hong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and Devices(GDSTC No.2019B121205001)International Collaboration project(No.121631KYSB20190026)+4 种基金The Hong Kong Polytechnic University(Grant Nos.1-ZVSQ,UAEZ)X.Zhou acknowledges financial support from National Natural Science Foundation of China(NSFC)(Grant No.11674040,11904039)the Fundamental Research Funds for the Central Universities(Grant no.2018CDQYWL0048,106112017CDJQJ308821 and 2018CDPTCG0001/26)H.W.acknowledges the support from the National Natural Science Foundation of China(Grant No.12004441,92165204)the Hundreds of Talents program of Sun Yat-sen University and the Fundamental Research Funds for the Central Universities(No.20lgpy165,202lqntd27).
文摘Achieving high thermoelectric pe rformance in thin fiIm heterostructures is essental for integrated and minlatured ther moelectric device applcations.In this work,we d emonstrate a mechansm and device performance of enh anced themoelectnic perfomance induced by interfuclal effect in a tansitdon metal dichalcogenides SrTiO_(3)(STO)heterpstructure Owing to the fomed conductive interface and elevated conductivity.the ZrTe_(2)/STO he teras tructure presents large thermoelectric power factor of 3.7×10^(5)μWcm^(-1)K^(-2) at 10 K.Fomat ion of quasi-wo dimensional conductance at the interface s atributed for the lage Seebeck coffcent and high electnical conductivity leading to high thermoelectric perfor mance which is demonstrated by a prototype device attaining 3 K cooling with 100 mA current input to this heterostructure This supenior themoelectnic property makes this he teros tructure a promtsing candidate for future thermoelectric device.
基金supported by the Hong Kong RGF grant(No.BQ-994)the National Science Foundation of China(NSFC)(Grant Nos.90923013,50902046).
文摘Bi_(0.85)La_(0.15)FeO_(3)(BLFO)nanotubes with an average diameter of about 200 nm and wall thickness of about 20 nm are fabricated by solgel alumina template technique,and their room-temperature multiferroic properties are studied.Piezoelectricity and ferroelectricity in the BLFO nanotubes are revealed by piezoresponse force microscopy study of individual nanotube.Doping the BiFeO_(3)nanotubes with La reduces the crystallization temperature and results in a reduced lose of Bi and therefore improved multiferroic properties of the nanotubes.Enhanced weak ferromagnetism is also observed,and it is attributed to the nano-crystalline structure of the nanotubes.
