Facile intercalation of alkali ions in WO_(3)for modulated electronic and optical properties:Implications for artificial synapses and chromogenic application  

作　　者：Changmeng Huan Zihan Lu Silin Tang Yongqing Cai Qingqing Ke 

机构地区：[1]School of Microelectronics Science and Technology,Sun Yat-sen University,Zhuhai 519082,China [2]Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems,Sun Yat-sen University,Zhuhai 519082,China [3]Institute of Applied Physics and Materials Engineering,University of Macao,Taipa,Macao 999078,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2024年第2期149-160,共12页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the Guangdong Basic and Applied Basic Research Foundation(Grant No.2021B1515120025);the Guangdong Province International Science and Technology Cooperation Research Project(Grant No.2023A0505050101);the National Natural Science Foundation of China(Grant No.22022309);the Science and Technology Development Fund from Macao SAR(Grant Nos.0120/2023/RIA2,0085/2023/ITP2,and FDCT-0163/2019/A3);the Natural Science Foundation of Guangdong Province,China(Grant No.2021A1515010024);the University of Macao(Grant No.MYRG2020-00075-IAPME)。

摘　　要：Tungsten oxides(WO_(3))are widely recognized as multifunctional systems owing to the existence of rich polymorphs.These diverse phases exhibit distinct octahedra-tilting patterns,generating substantial tunnels that are ideally suited for iontronics.However,a quantitative comprehension regarding the impact of distinct phases on the kinetics of intercalated conducting ions remains lacking.Herein,we employ first-principles calculations to explore the spatial and orientational correlations of ion transport inγ-and h-WO_(3),shedding light on the relationship between diffusion barriers and the size of the conducting ions.Our findings reveal that different types and concentrations of alkali-metals induce distinct and continuous lattice distortions in WO_(3)polymorphs.Specifically,γ-WO_(3)is more appropriate to accommodate Li+ions,exhibiting a diffusion barrier and coefficient of 0.25 eV and 9.31×10^(-8)cm^(2)s^(-1),respectively.Conversely,h-WO_(3)features unidirectional and sizeable tunnels that facilitate the transport of K+ions with an even lower barrier and a high coefficient of 0.11 e V and 2.12×10^(-5)cm^(2)s^(-1),respectively.Furthermore,the introduction of alkali-metal into WO_(3)tunnels tends to introduce n-type conductivity by contributing s-electrons to the unoccupied W 5d states,resulting in enhanced conductivity and tunable electronic structures.These alkali metals in WO_(3)tunnels are prone to charge transfer,forming small polaronic states and modulating the light absorption in the visible and nearinfrared regions.These tunable electronic and optical properties,combined with the high diffusion coefficient,underscore the potential of WO_(3)in applications such as artificial synapses and chromogenic devices.

关 键 词：WO_(3)polymorphs ion insertion kinetic activity tunable electronic and optical properties iontronics 

分 类 号：O469[理学—凝聚态物理]