-
由于石墨烯在太赫兹波范围内只发生带内跃迁，相比在可见光范围内，其光学吸收特性有显著优势，通过集成石墨烯与谐振腔，将太赫兹波限制在腔内，可进一步增强石墨烯对太赫兹波的吸收. 采用麦克斯韦方程组并结合电磁场边界条件，研究了单层石墨烯在太赫兹波段范围内的光吸收机理；推导出石墨烯的传输矩阵和吸收系数方程，发现在太赫兹波段石墨烯的吸收是在可见光波段吸收的9-22倍；通过建立谐振腔型石墨烯光电探测器在太赫兹波段的光吸收模型及求解探测器吸收率方程，发现在0.12 THz处，吸收率可达0.965，相比无腔状态下石墨烯在太赫兹波段的最大吸收率0.5，提高了93%；优化设计器件结构参数并表征，最终器件响应度最高达到236.7 A/W，半高全宽为0.035 THz. 理论分析表明，采用谐振腔型石墨烯光电探测器对太赫兹波进行探测，具有高吸收率、高响应度. 研究结果对于太赫兹谐振腔型石墨烯光电探测器的设计和应用提供了理论参考.Detection of the terahertz (THz) electromagnetic spectrum(wavelengths range 0.03-3 mm) is a promising technique for a large variety of strategic applications, such as biomedical diagnostics and process, quality control, homeland security, and environmental monitoring, etc. Graphene has been recognized internationally to have dominant advantages in photodetectors operating due to its high carrier mobility, gapless spectrum, and frequency-independent absorption coefficient. Graphene photodetector operating in the THz region has been extensively studied with great interests. A graphene microcavity photodetector with THz electromagnetic spectrum is demonstrated in this paper, and its responsivity and detectivity under THz electromagnetic spectrum are evaluated. In the designed device, we adopt a distributed bragger reflection (DBR) consisting of two semiconductor materials SiO2 and TiO2 to form an alternating cavity with high-finesse planar, sandwich the absorbing graphene layer between the cavitys top and bottom layers, and design the DBRs reflectivity by the optical transmission matrix method. The monolayer graphenes optical absorption mechanism of the THz radiation spectrum is studied by the conductivity matrix and Maxwells equations with the electromagnetic boundary conditions. Graphenes transfer matrix and absorption coefficient equation are further derived. It is found that at THz region, graphenes conductivity plays an important role in its absorptionand its absorption is 9-22 times enhanced compared with that at the visible region. An optical absorption model of microcavity-enhanced graphene photodetector at THz region is established. The photodetectors absorption rate and responsitivity are analyzed specifically. Theoretical analysis shows that absorption rate is symmetrical to the microcavitys center position and changes periodically, and the shift of the microcavity length influences the period numbers. The maximum rate of the photodetectors absorption reaches 0.965 at 0.12 THz, which increases 93% compared with its maximum absorption rate 0.5 with no cavity. The optimal structure parameters for the designed photodetector are as follows, the top and bottom mirrors reflectivity are 0.928 and 0.998 respectively, the microcavity length is 2.5 mm, the graphene is 0.035 mm away from the top mirror. Under the optimal structure, the photodetectors responsivity reaches 236.7 A/W, and its full width at half maximum reaches 0.035 THz. The designed graphene microcavity photodetector can exhibit high responsivity and detectivity in THz radiation spectrum.
-
Keywords:
- graphene photodetector /
- microcavity /
- terahertz /
- absorption rate
[1] Yoneyama H, Yamashita M, Kasai S, Kawase K, Ito H, Ouchi T 2008 Opt. Commun. 281 1909
[2] Liu S G, Zhong R B 2009 Journal of University of Electronic Science and Technology of China 38 481
[3] Zhang Z L, Mu K J, Zhang C L 2009 Science and Technology 8 11
[4] Li H, Cao J C, Han Y J, Guo X G, Tan Z Y, Lue J T, Luo H, Laframboise S R, Liu H C 2008 J. Appl. Phys. 104 043101
[5] Williams B S 2007 Nat. Photonics 1 517
[6] Guo X G, Tan Z Y, Cao J C, Liu H C 2009 Appl. Phys. Lett. 94 201101
[7] Luo H, Liu H C, Song C Y, Wasilewski Z R 2005 Appl. Phys. Lett. 86 231103
[8] Zhang R, Guo X G, Cao J C 2011 Acta Phys. Sin. 60 050705 (in Chinese) [张戎, 郭旭光, 曹俊诚 2011 物理学报 60 050705]
[9] Phaedon A 2010 Nano Lett. 10 4285
[10] Bolotin K I, Sikes K J, Jiang Z, Klima M, Fudenberg G, Hone J, Kim P, Stormer H L 2008 Solid State Commun. 146 351
[11] Wright A R, Cao J C, Zhang C 2009 Phys. Rev. Lett. 103 207401
[12] Ryzhii M, Otsuji T, Mitin V, Ryzhii V 2011 Jpn. J. Appl. Phys. 50 070117
[13] Vicarelli L, Vitiello M S, Coquillat D, Lombardo A, Ferrari A C, Knap W, Polini M, Pellegrini V, Tredicucci A 2012 Nat. Mater. 11 865
[14] Mittendorff M, Winnerl S, Kamann J, Eroms J, Weiss D, Schneider H, Helm M 2013 Appl. Phys. Lett. 103 021113
[15] Muraviev A V, Rumyantsev S L, Liu G, Balandin A A, Knap W, Shur M S 2013 Appl. Phys. Lett. 103 181114
[16] Zak A, Andersson M A, Bauer M, Matukas J, Lisauskas A, Roskos H G, Stake J 2014 Nano Lett. 14 5834
[17] Spirito D, Coquillat D, Bonis S L, Lombardo A, Bruna M, Ferrari A C, Pellegrini V, Tredicucci A, Knap W, Vitiello M S 2014 Appl. Phys. Lett. 104 061111
[18] Engel M, Steiner M, Lombardo A, Ferrari A C, Lohneysen H V, Avouris P, Krupke R 2012 Nat. Commun. 3 906
[19] Furchi M M, Urich A, Pospischil A, Lilley G, Unterrainer K, Detz H 2012 Nano Lett. 12 2773
[20] Xia F N, Mueller T, Lin Y M, Valdes-Garcia A, Avouris P 2009 Nat. Nanotechnol. 4 839
[21] Deng X H, Liu J T, Yuan J R, Wang T B 2015 Acta Phys. Sin. 64 057801 (in Chinese) [邓新华, 刘江涛, 袁吉仁, 王同标 2015 物理学报 64 057801]
[22] Dong H M, Zhang J, Peeters F M, Xu W 2009 J. Appl. Phys. 106 043103
[23] Chen Y L, Feng X B, Hou D D 2013 Acta Phys. Sin. 62 187301 (in Chinese) [陈英良, 冯小波, 侯德东 2013 物理学报 62 187301]
[24] Horng J, Chen C F, Geng B, Girit C, Zhang Y, Hao Z, Bechtel H A, Martin M, Zettl A, Crommie M F, Shen Y R, Wang F 2011 Phys. Rev. B 83 165113
[25] Song S F 2012 Laser & Infrared 42 1367
[26] Zhou Y 2009 M. S. Thesis (Chengdu: University of Electronic Science and Technology of China) (in Chinese) [周勇 2009 硕士学位论文 (成都: 电子科技大学)]
[27] Ferreira A, Peres N M R, Ribeiro R M, Stauber T 2012 Phys. Rev. B 85 115438
-
[1] Yoneyama H, Yamashita M, Kasai S, Kawase K, Ito H, Ouchi T 2008 Opt. Commun. 281 1909
[2] Liu S G, Zhong R B 2009 Journal of University of Electronic Science and Technology of China 38 481
[3] Zhang Z L, Mu K J, Zhang C L 2009 Science and Technology 8 11
[4] Li H, Cao J C, Han Y J, Guo X G, Tan Z Y, Lue J T, Luo H, Laframboise S R, Liu H C 2008 J. Appl. Phys. 104 043101
[5] Williams B S 2007 Nat. Photonics 1 517
[6] Guo X G, Tan Z Y, Cao J C, Liu H C 2009 Appl. Phys. Lett. 94 201101
[7] Luo H, Liu H C, Song C Y, Wasilewski Z R 2005 Appl. Phys. Lett. 86 231103
[8] Zhang R, Guo X G, Cao J C 2011 Acta Phys. Sin. 60 050705 (in Chinese) [张戎, 郭旭光, 曹俊诚 2011 物理学报 60 050705]
[9] Phaedon A 2010 Nano Lett. 10 4285
[10] Bolotin K I, Sikes K J, Jiang Z, Klima M, Fudenberg G, Hone J, Kim P, Stormer H L 2008 Solid State Commun. 146 351
[11] Wright A R, Cao J C, Zhang C 2009 Phys. Rev. Lett. 103 207401
[12] Ryzhii M, Otsuji T, Mitin V, Ryzhii V 2011 Jpn. J. Appl. Phys. 50 070117
[13] Vicarelli L, Vitiello M S, Coquillat D, Lombardo A, Ferrari A C, Knap W, Polini M, Pellegrini V, Tredicucci A 2012 Nat. Mater. 11 865
[14] Mittendorff M, Winnerl S, Kamann J, Eroms J, Weiss D, Schneider H, Helm M 2013 Appl. Phys. Lett. 103 021113
[15] Muraviev A V, Rumyantsev S L, Liu G, Balandin A A, Knap W, Shur M S 2013 Appl. Phys. Lett. 103 181114
[16] Zak A, Andersson M A, Bauer M, Matukas J, Lisauskas A, Roskos H G, Stake J 2014 Nano Lett. 14 5834
[17] Spirito D, Coquillat D, Bonis S L, Lombardo A, Bruna M, Ferrari A C, Pellegrini V, Tredicucci A, Knap W, Vitiello M S 2014 Appl. Phys. Lett. 104 061111
[18] Engel M, Steiner M, Lombardo A, Ferrari A C, Lohneysen H V, Avouris P, Krupke R 2012 Nat. Commun. 3 906
[19] Furchi M M, Urich A, Pospischil A, Lilley G, Unterrainer K, Detz H 2012 Nano Lett. 12 2773
[20] Xia F N, Mueller T, Lin Y M, Valdes-Garcia A, Avouris P 2009 Nat. Nanotechnol. 4 839
[21] Deng X H, Liu J T, Yuan J R, Wang T B 2015 Acta Phys. Sin. 64 057801 (in Chinese) [邓新华, 刘江涛, 袁吉仁, 王同标 2015 物理学报 64 057801]
[22] Dong H M, Zhang J, Peeters F M, Xu W 2009 J. Appl. Phys. 106 043103
[23] Chen Y L, Feng X B, Hou D D 2013 Acta Phys. Sin. 62 187301 (in Chinese) [陈英良, 冯小波, 侯德东 2013 物理学报 62 187301]
[24] Horng J, Chen C F, Geng B, Girit C, Zhang Y, Hao Z, Bechtel H A, Martin M, Zettl A, Crommie M F, Shen Y R, Wang F 2011 Phys. Rev. B 83 165113
[25] Song S F 2012 Laser & Infrared 42 1367
[26] Zhou Y 2009 M. S. Thesis (Chengdu: University of Electronic Science and Technology of China) (in Chinese) [周勇 2009 硕士学位论文 (成都: 电子科技大学)]
[27] Ferreira A, Peres N M R, Ribeiro R M, Stauber T 2012 Phys. Rev. B 85 115438
计量
- 文章访问数: 5713
- PDF下载量: 532
- 被引次数: 0
下载:
