Recent progress on two-dimensional ferroelectrics: Material systems and device applications

doi:10.1088/1674-1056/ad08a4

中国物理B ›› 2023, Vol. 32 ›› Issue (12): 128508-128508.doi: 10.1088/1674-1056/ad08a4

所属专题： SPECIAL TOPIC—Post-Moore era: Materials and device physics

Recent progress on two-dimensional ferroelectrics: Material systems and device applications

Zhiwei Fan(范芷薇)^1,†, Jingyuan Qu(渠靖媛)^1,†, Tao Wang(王涛)¹, Yan Wen(温滟)¹, Ziwen An(安子文)¹, Qitao Jiang(姜琦涛)¹, Wuhong Xue(薛武红)^1,‡, Peng Zhou(周鹏)^2,§, and Xiaohong Xu(许小红)^1,¶

1 Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education and School of Chemistry and Materials Science, Shanxi Normal University, Taiyuan 030031, China;
2 State Key Laboratory of ASIC & System, School of Microelectronics, Fudan University, Shanghai 200433, China

收稿日期:2023-07-31 修回日期:2023-10-20 接受日期:2023-11-02 出版日期:2023-11-14 发布日期:2023-11-27
通讯作者: Wuhong Xue, Peng Zhou, Xiaohong Xu E-mail:xuewuhong@sxnu.edu.cn;pengzhou@fudan.edu.cn;xuxh@sxnu.edu.cn
基金资助:
Project supported by the National Key Research and Development Program of China (Grant No.2022YFB3505301), the National Natural Science Foundation of China (Grant Nos.12241403 and12174237), and the Graduate Education Innovation Project in Shanxi Province (Grant No.2021Y484).

Recent progress on two-dimensional ferroelectrics: Material systems and device applications

1 Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education and School of Chemistry and Materials Science, Shanxi Normal University, Taiyuan 030031, China;
2 State Key Laboratory of ASIC & System, School of Microelectronics, Fudan University, Shanghai 200433, China

Received:2023-07-31 Revised:2023-10-20 Accepted:2023-11-02 Online:2023-11-14 Published:2023-11-27
Contact: Wuhong Xue, Peng Zhou, Xiaohong Xu E-mail:xuewuhong@sxnu.edu.cn;pengzhou@fudan.edu.cn;xuxh@sxnu.edu.cn
Supported by:
Project supported by the National Key Research and Development Program of China (Grant No.2022YFB3505301), the National Natural Science Foundation of China (Grant Nos.12241403 and12174237), and the Graduate Education Innovation Project in Shanxi Province (Grant No.2021Y484).

摘要/Abstract

摘要： Ferroelectrics are a type of material with a polar structure and their polarization direction can be inverted reversibly by applying an electric field. They have attracted tremendous attention for their extensive applications in non-volatile memory, sensors and neuromorphic computing. However, conventional ferroelectric materials face insulating and interfacial issues in the commercialization process. In contrast, two-dimensional (2D) ferroelectric materials usually have excellent semiconductor performance, clean van der Waals interfaces and robust ferroelectric order in atom-thick layers, and hold greater promise for constructing multifunctional ferroelectric optoelectronic devices and nondestructive ultra-high-density memory. Recently, 2D ferroelectrics have obtained impressive breakthroughs, showing overwhelming superiority. Herein, firstly, the progress of experimental research on 2D ferroelectric materials is reviewed. Then, the preparation of 2D ferroelectric devices and their applications are discussed. Finally, the future development trend of 2D ferroelectrics is looked at.

关键词: two-dimensional materials, ferroelectrics, device applications

Abstract: Ferroelectrics are a type of material with a polar structure and their polarization direction can be inverted reversibly by applying an electric field. They have attracted tremendous attention for their extensive applications in non-volatile memory, sensors and neuromorphic computing. However, conventional ferroelectric materials face insulating and interfacial issues in the commercialization process. In contrast, two-dimensional (2D) ferroelectric materials usually have excellent semiconductor performance, clean van der Waals interfaces and robust ferroelectric order in atom-thick layers, and hold greater promise for constructing multifunctional ferroelectric optoelectronic devices and nondestructive ultra-high-density memory. Recently, 2D ferroelectrics have obtained impressive breakthroughs, showing overwhelming superiority. Herein, firstly, the progress of experimental research on 2D ferroelectric materials is reviewed. Then, the preparation of 2D ferroelectric devices and their applications are discussed. Finally, the future development trend of 2D ferroelectrics is looked at.

Key words: two-dimensional materials, ferroelectrics, device applications

中图分类号: (Semiconductor devices)

85.30.-z

77.80.-e (Ferroelectricity and antiferroelectricity) 28.52.Fa (Materials)

Zhiwei Fan(范芷薇), Jingyuan Qu(渠靖媛), Tao Wang(王涛), Yan Wen(温滟), Ziwen An(安子文), Qitao Jiang(姜琦涛), Wuhong Xue(薛武红), Peng Zhou(周鹏), and Xiaohong Xu(许小红). Recent progress on two-dimensional ferroelectrics: Material systems and device applications[J]. 中国物理B, 2023, 32(12): 128508-128508.

参考文献

[1] Valasek J 1921 Phys. Rev. 17 475
[2] Busch G and Scherrer P 1935 Naturwissenschaften 23 737
[3] Von Hippel A 1950 Rev. Mod. Phys. 22 221
[4] Furukawa T 1984 Ferroelectrics 57 63
[5] Yagi T, Tatemoto M and Sako J I 1980 Polym. J. 12 209
[6] Bune A V, Fridkin V M, Ducharme S, Blinov L M, Palto S P, Sorokin A V, Yudin S G and Zlatkin A 1998 Nature 391 874
[7] Ji D X, Cai S H, Paudel T R, Sun H Y, Zhang C C, Han L, Wei Y F, Zang Y P, Gu M and Zhang Y 2019 Nature 570 87
[8] Cheema S S, Kwon D, Shanker N, Reis Rd, Hsu S L, Xiao J, Zhang H G, Wagner R, Datar A and McCarter M R 2020 Nature 580 478
[9] Novoselov K S, Geim A K, Morozov S V, Jiang D, Zhang Y, Dubonos S V, Grigorieva I V and Firsov A A 2004 Science 306 666 10a Chhowalla M, Shin H S, Eda G, Li L J, Loh K P and Zhang H 2013 Nat. Chem. 5 263 10b Huang X, Zeng Z and Zhang H 2013 Chem. Soc. Rev. 42 1934 10c Chhowalla M, Liu Z and Zhang H 2015 Chem. Soc. Rev. 44 2584
[11] Wang Q H, Kalantar-Zadeh K, Kis A, Coleman J N and Strano M S 2012 Nat. Nanotechnol. 7 699
[12] Lin Y, Williams T V and Connell J W 2010 J. Phys. Chem. Lett. 1 277 13a Anasori B, Lukatskaya M R and Gogotsi Y 2017 Nat. Rev. 2 16098 13b Naguib M, Mochalin V N, Barsoum M W and Gogotsi Y 2014 Adv. Mater. 26 992
[14] Chandrasekaran A, Mishra A and Singh A K 2017 Nano Lett. 17 3290 15a Houssa M, Scalise E, Sankaran K, Pourtois G, Afanas'ev V V and Stesmans A 2011 Appl. Phys. Lett. 98 223107 15b Senger R T, Tongay S, Durgun E and Ciraci S 2005 Phys. Rev. B 72 075419 15c Lalmi B, Oughaddou H, Enriquez H, Kara A, Vizzini S, Ealet B and Aufray B 2010 Appl. Phys. Lett. 97 223109 15d Liu H, Du Y C, Deng Y X and Ye P D 2015 Chem. Soc. Rev. 44 2732 15e Kara A, Enriquez H, Seitsonen A P, Lew Yan Voon L C, Vizzini S, Aufray B and Oughaddou H 2012 Surf. Sci. Rep. 67 1 15f Bianco E, Butler S, Jiang S S, Restrepo O D, Windl W and Goldberger J E 2013 ACS Nano 7 4414 16a Peng Y, Li Y S, Ban Y J, Jin H, Jiao W M, Liu X L and Yang W S 2014 Science 346 1356 16b Rodenas T, Luz I, Prieto G, Seoane B, Miro H, Corma A, Kapteijn F, Xamena F X L I and Gascon J 2015 Nat. Mater. 14 48 16c Colson J W, Woll A R, Mukherjee A, Levendorf M P, Spitler E L, Shields V B, Spencer M G, Park J and Dichtel W R 2011 Science 332 228 16d Kory M J, Wörle M, Weber T, Payamyar P, Poll Stan W van de, Dshemuchadse J, Trapp N and Schlüter A D 2014 Nat. Chem. 6 779 16e Kissel P, Murray D J, Wulftange W J, Catalano V J and King B T 2014 Nat. Chem. 6 774
[17] Wu J B, Chen H Y, Yang N, Cao J, Yan X D, Liu F X, Sun Q B, Ling X, Guo J and Wang H 2020 Nat. Electron. 3 466
[18] Liu F C, You L, Seyler K L, Li X B, Yu P, Lin J H, Wang X W, Zhou J D, Wang H and He H Y 2016 Nat. Commun. 7 12357
[19] Wan S Y, Li Y, Li W, Mao X Y, Zhu W G and Zeng H L 2018 Nanoscale 10 14885
[20] Wang X W, Yu P, Lei Z D, Zhu C, Cao X, Liu F C, You L, Zeng Q S, Deng Y and Zhu C 2019 Nat. Commun. 10 3037
[21] Si M W, Saha A K, Gao S J, Qiu G, Qin J K, Duan Y Q, Jian J, Niu C, Wang H Y and Wu W Z 2019 Nat. Electron. 2 580
[22] Xue F, He X, Liu W H, Periyanagounder D, Zhang C H, Chen M G, Lin C H, Luo L Q, Yengel E and Tung V 2020 Adv. Funct. Mater. 30 2004206
[23] Xue W H, Gao C H, Zhang Z, Han T T, Hou N, Yin W H, Shi L, Wang X L, Liu G, Xu X H 2023 Sci. China Mater. 66 764
[24] Belianinov A, He Q, Dziaugys A, Maksymovych P, Eliseev E, Borisevich A, Morozovska A, Banys J, Vysochanskii Y and Kalinin S V 2015 Nano Lett. 15 3808
[25] Susner M A, Belianinov A, Borisevich A, He Q, Chyasnavichyus M, Demir H, Sholl D S, Ganesh P, Abernathy D L, McGuire M A and Maksymovych P 2015 ACS Nano 9 12365
[26] Huang Y T, Chen N K, Li Z Z, Wang X P, Sun H B, Zhang S B and Li X B 2022 InfoMat. 4 e12341
[27] Abrahams S C 1990 Ferroelectrics 104 37
[28] Ding W J, Zhu J B, Wang Z, Gao Y F, Xiao D, Gu Y, Zhang Z Y and Zhu W G 2017 Nat. Commun. 8 14956
[29] Cui C J, Hu W J, Yan X X, Addiego C, Gao W P, Wang Y, Wang Z, Li L Z, Cheng Y C and Li P 2018 Nano Lett. 18 1253
[30] Poh S M, Tan S J R, Wang H, Song P, Abidi I H, Zhao X X, Dan J D, Chen J S, Luo Z T and Pennycook S J 2018 Nano Lett. 18 6340
[31] Xue F, Hu W J, Lee K C, Lu L S, Zhang J W, Tang H L, Han A, Hsu W T, Tu S B and Chang W H 2018 Adv. Funct. Mater. 28 1803738
[32] Io W F, Yuan S G, Pang S Y, Wong L W, Zhao J and Hao J H T 2020 Nano Res. 13 1897
[33] Lv B H, Yan Z, Xue W H, Yang R L, Li J Y, Ci W J, Pang R X, Zhou P, Liu G and Liu Z Y 2021 Mater. Horiz. 8 1472
[34] Lv B H, Xue W H, Yan Z, Yang R L, Wu H, Wang P, Zhang Y Y, Hou J N, Zhu W G and Xu X H 2022 Sci. China Mater. 65 1639
[35] Hu H, Sun Y, Chai M, Xie D, Ma J and Zhu H 2019 Appl. Phys. Lett. 114 252903
[36] Hu H, Wang H, Sun Y, Li J, Wei J, Xie D and Zhu H 2021 Nanotechnology 32 385202
[37] Wu M H and Zeng X C 2016 Nano Lett. 16 3236
[38] Higashitarumizu N, Kawamoto H, Lee C J, Lin B H, Chu F H, Yonemori I, Nishimura T, Wakabayashi K, Chang W H and Nagashio K 2020 Nat. Commun. 11 2428
[39] Anderson P P W and Blount E I 1965 Phys. Rev. Let. 14 217
[40] Shi Y G, Guo Y F, Wang X, Princep A J, Khalyavin D, Manuel P, Michiue Y, Sato A, Tsuda K and Yu S 2013 Nat. Mater. 12 1024
[41] Fei Z Y, Zhao W J, Palomaki T A, Sun B S, Miller M K, Zhao Z Y, Yan J Q, Xu X D and Cobden D H 2018 Nature 560 336
[42] Sharma P, Xiang F X, Shao D F, Zhang D, Tsymbal E Y, Hamilton A R and Seidel J 2019 Sci. Adv. 5 eaax5080
[43] Ma X Y, Lyu H Y, Hao K R, Zhao Y M, Qian X F, Yan Q B and Su G 2021 Sci. Bull. 66 233 44a Qi L, Ruan S C and Zeng Y J 2021 Adv. Mater. 33 2005098 44b Xiao C C, Xu Z A, Luo X and Lu Y H 2001 arXiv 03164 [cond-mat.mes-hall]
[45] Yuan S G, Luo X, Chan H L, Xiao C C, Dai Y W, Xie M H and Hao J H 2019 Nat. Commun. 10 1775
[46] Wu M H and Li J 2021 P. Natl. Acad. Sci. USA 118 e211570311
[47] Wu M H 2021 ACS Nano 15 9229
[48] Li L and Wu M H 2017 ACS Nano 11 6382
[49] Xiao J, Wang Y, Wang H, Pemmaraju C D, Wang S Q, Muscher P, Sie E J, Nyby C M and Devereaux T P 2020 Nat. Phys. 16 1028
[50] Yasuda K J, Wang X R, Watanabe K J, Taniguchi T and Jarillo-Herrero P 2021 Science 372 1458
[51] Wan Y, et al. 2022 Phys. Rev. Lett. 128 067601
[52] Wang X, Yasuda K, Zhang Y, Liu S, Watanabe K, Taniguchi T, Hone J and Fu L, Jarillo-Herrero P 2022 Nat. Nanotechnol. 17 367
[53] Weston A, et al. 2022 Nat. Nanotechnol. 17 390
[54] Sui F, Jin M, Zhang Y, Qi R, Wu Y N, Huang R, Yue F and Chu J 2023 Nat. Commun. 14 36
[55] Meng P, Wu Y, Bian R, Pan E, Dong B, Zhao X X, Chen J G, Wu L S, Sun Y Q and Fu Q D 2022 Nat. Commun. 13 7696
[56] Deb S, Cao W, Raab N, Watanabe K J, Taniguchi T, Goldstein M, Kronik L, Urbakh M, Hod O and Shalom M B 2022 Nature 612 465
[57] Vizner Stern M, Waschitz Y, Cao W, Nevo I, Watanabe K, Taniguchi T, Sela E, Urbakh M, Hod O and Ben Shalom M 2021 Science 372 1462
[58] Zheng Z, Ma Q, Bi Z, et al. 2020 Nature 588 71
[59] Yang L, Ding S P, Gao J H and Wu M H 2023 Phys. Rev. Lett. 131 096801
[60] Zhao Y H, Lin L F, Zhou Q H, Li Y H, Yuan S J, Chen Q, Dong S and Wang J L 2018 Nano Lett. 18 2943
[61] He R, Lin J L, Liu Q, Liao Z L, Shui L L, Wang Z J, Zhong Z C and Li R W 2020 ACS Appl. Mater. Interfaces 12 45602
[62] Xue W H, Jiang Q T, Wang F K, He R, Pang R X, Yang L, Wang P, Yang R L, Zhong Z C and Zhai T Y 2022 Small 18 2105599
[63] Si M W, Saha A K, Gao S J, Qiu G, Qin J K, Duan Y Q, Jian J, Niu C, Wang H Y and Wu W Z 2019 Nat. Electron. 2 580
[64] Liao J, Wen W, Wu J, Zhou Y, Hussain S, Hu H, Li J, Liaqat A, Zhu H, Jiao L, Zheng Q and Xie L 2023 ACS Nano 17 6095
[65] Xue F, He X, Liu W H, Periyanagounder D, Zhang C H, Chen M G, Lin C H, Luo L Q, Yengel E and Tung V 2020 Adv. Funct. Mater. 30 2004206
[66] Lv B H, Xue W H, Yan Z, Yang R L, Wu H, Wang P, Zhang Y Y, Hou J N, Xu X H and Zhu W G 2022 Sci. China Mater. 65 1639
[67] Liu K, Zhang T, Dang B, et al. 2022 Nat. Electron. 5 761
[68] Kwon K C, Zhang Y S, Wang L, Yu W, Wang X J, Park I H, Choi H S, Ma T, Zhu Z Y and Tian B B 2020 ACS Nano 14 7628
[69] Fei Xue, Xin He, Zhenyu Wang, et al. 2021 Adv. Mater. 33 2008709
[70] Zhang Y J, Ideue T, Onga M, Qin F, Suzuki R, Zak A, Tenne R, Smet J H and Iwasa Y 2019 Nature 570 349
[71] Akamatsu T, Ideue T, Zhou L, Dong Y, Kitamura S, Yoshii M, Yang D, Onga M, Nakagawa Y and Watanabe K 2021 Science 372 68
[72] Jiang J, Chen Z, Hu Y, Xiang Y, Zhang L, Wang Y, Wang G C and Shi J 2021 Nat. Nanotechnol. 16 894
[73] Spanier J E, Fridkin V M, Rappe A M, Akbashev A R, Polemi A, Qi Y B, Gu Z Q, Young S M, Hawley C J and Imbrenda D 2016 Nat. Photonics 10 611
[74] Li Y, Fu J, Mao X, Chen C, Liu H, Gong M, Zeng H 2021 Nat. Commun. 12 5896
[75] Dong Y, Yang M M, Yoshii M, Matsuoka S, Kitamura S, Hasegawa T, Ogawa N, Morimoto T, Ideue T and Iwasa Y 2023 Nat. Nanotechnol. 18 36
[76] Xiao R C, Gao Y, Jiang H, Gan W, Zhang C and Li H 2022 npj Comput. Mater. 8 138
[77] Kim J, Kim K W, Shin D, Lee S H, Sinova J, Park N and Jin H 2019 Nat. Commun. 10 3965
[78] Wang H and Qian X 2019 Sci. Adv. 5 eaav9743
[79] Wang H and Qian X 2019 npj Comput. Mater. 5 119
[80] Pantel D, Goetze S, Hesse D and Alexe M 2012 Nat. Mater. 11 289
[81] Garcia V, Bibes M, Bocher L, Valencia S, Kronast F, Crassous A, Moya X, Enouz-vedrenne S, Gloter A and Imhof D 2010 Science 327 1106
[82] Wen Z, Li C, Wu D, Li A D and Ming N B 2013 Nat. Mater. 12 617
[83] Wu J B, Chen H Y, Yang N, Cao J, Yan X D, Liu F X, Sun Q B, Ling X, Guo J and Wang H 2020 Nat. Electron. 3 466
[84] Yang J, Zhou J, Lu J, Luo Z C, Yang J B and Shen L 2022 Mater. Horiz. 9 1422
[85] Ding J, Shao D F, Li M, Wen L W and Tsymbal E Y 2021 Phys. Rev. Lett. 126 057601

[1]	Ming Yan(闫明), Zhi-Yuan Xie(谢志远), and Miao Gao(高淼). High-temperature ferromagnetism and strong π-conjugation feature in two-dimensional manganese tetranitride[J]. 中国物理B, 2023, 32(3): 37104-037104.
[2]	Ming Mei(梅明), Zheng Chen(陈正), Yong Nie(聂勇), Yuanyuan Wang(王园园), Xiangde Zhu(朱相德), Wei Ning(宁伟), and Mingliang Tian(田明亮). Magnetic and magnetotransport properties of layered TaCoTe₂ single crystals[J]. 中国物理B, 2023, 32(12): 127303-127303.
[3]	Shuhang Qian(钱树航), Kai Wang(王凯), Jiaxing Yang(杨加兴), Chao Guan(关超), Hua Long(龙华), and Peixiang Lu(陆培祥). Multifunctional light-field modulation based on hybrid nonlinear metasurfaces[J]. 中国物理B, 2023, 32(10): 107803-107803.
[4]	Zhi-Yuan Li(李志远) and Jian-Feng Chen(陈剑锋). Atomic-scale electromagnetic theory bridging optics in microscopic world and macroscopic world[J]. 中国物理B, 2023, 32(10): 104211-104211.
[5]	Ke Xu(徐可), Junsheng Feng(冯俊生), and Hongjun Xiang(向红军). Computational studies on magnetism and ferroelectricity[J]. 中国物理B, 2022, 31(9): 97505-097505.
[6]	Qiong Wu(吴琼), Lei Zhao(赵雷), Xinghao Chen(陈兴豪), and Shifeng Zhao(赵世峰)^†. Efficiently enhanced energy storage performance of Ba₂Bi₄Ti₅O₁₈ film by co-doping Fe³⁺ and Ta⁵⁺ ion with larger radius[J]. 中国物理B, 2022, 31(9): 97701-097701.
[7]	Xiao-Fang Ouyang(欧阳小芳) and Lu Wang(王路). Half-metallicity induced by out-of-plane electric field on phosphorene nanoribbons[J]. 中国物理B, 2022, 31(7): 77304-077304.
[8]	Kejian Liu(刘可鉴), Jian Li(李健), Qing-Xu Li(李清旭), and Jia-Ji Zhu(朱家骥). Anisotropic plasmon dispersion and damping in multilayer 8-Pmmn borophene structures[J]. 中国物理B, 2022, 31(11): 117303-117303.
[9]	Yu Xu(徐俞), Jianfeng Wang(王建峰), Bing Cao(曹冰), and Ke Xu(徐科). Epitaxy of III-nitrides on two-dimensional materials and its applications[J]. 中国物理B, 2022, 31(11): 117702-117702.
[10]	Yi-Di Pang(庞奕荻), En-Xiu Wu(武恩秀), Zhi-Hao Xu(徐志昊), Xiao-Dong Hu(胡晓东), Sen Wu(吴森), Lin-Yan Xu(徐临燕), and Jing Liu(刘晶). Effect of electrical contact on performance of WSe₂ field effect transistors[J]. 中国物理B, 2021, 30(6): 68501-068501.
[11]	Chun Zhou(周淳), Junchao Huang(黄俊超), and Xiangmei Duan(段香梅). Two-dimensional PC₃ as a promising anode material for potassium-ion batteries: First-principles calculations[J]. 中国物理B, 2021, 30(5): 56801-056801.
[12]	Yanchong Zhao(赵岩翀), Tao Bo(薄涛), Luojun Du(杜罗军), Jinpeng Tian(田金朋), Xiaomei Li(李晓梅), Kenji Watanabe, Takashi Taniguchi, Rong Yang(杨蓉), Dongxia Shi(时东霞), Sheng Meng(孟胜), Wei Yang(杨威), and Guangyu Zhang(张广宇). Thermally induced band hybridization in bilayer-bilayer MoS₂/WS₂ heterostructure[J]. 中国物理B, 2021, 30(5): 57801-057801.
[13]	Yuanjie Chen(陈元杰), Shaoyun Huang(黄少云), Jingwei Mu(慕经纬), Dong Pan(潘东), Jianhua Zhao(赵建华), and Hong-Qi Xu(徐洪起). A double quantum dot defined by top gates in a single crystalline InSb nanosheet[J]. 中国物理B, 2021, 30(12): 128501-128501.
[14]	Xiaolong Feng(冯晓龙), Jiaojiao Zhu(朱娇娇), Weikang Wu(吴维康), and Shengyuan A. Yang(杨声远). Two-dimensional topological semimetals[J]. 中国物理B, 2021, 30(10): 107304-107304.
[15]	侯延辉, 张腾, 孙家涛, 刘立巍, 姚裕贵, 王业亮. Progress on 2D topological insulators and potential applications in electronic devices[J]. 中国物理B, 2020, 29(9): 97304-097304.

Recent progress on two-dimensional ferroelectrics: Material systems and device applications

Recent progress on two-dimensional ferroelectrics: Material systems and device applications

PDF (PC)

赞

可视化

摘要/Abstract

引用本文

使用本文

参考文献

相关文章 15

Metrics

本文评价

推荐阅读 0