Photodetectors based on graphene, other two-dimensional materials and hybrid systems

Nature Nanotechnology

Volumn 9, Issue 10, 2014, Pages 780-793

  Koppens, F H L ^a   Mueller, T ^b   Avouris, P ^c   Ferrari, A C ^d   Vitiello, M S ^e   Polini, M ^e,f  

^a ICFO INSTITUT DE CIENCIES FOTONIQUES   (Spain)

^b VIENNA UNIVERSITY OF TECHNOLOGY   (Austria)

^c IBM T J WATSON RESEARCH CENTER   (United States)

^d Cambridge Graphene Centre   (United Kingdom)

^e ISTITUTO NANOSCIENZE CNR   (Italy)

^f ISTITUTO ITALIANO DI TECNOLOGIA   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

GRAPHENE; HYBRID SYSTEMS; PHOTODETECTORS; PHOTONS; PLASMONIC NANOPARTICLES; PLASMONICS; SEMICONDUCTOR QUANTUM DOTS; SILICON DETECTORS; SILICON PHOTONICS; TRANSITION METALS;

ELECTRONIC TECHNOLOGIES; OPTOELECTRONIC APPLICATIONS; PHOTONIC COMPONENTS; TERAHERTZ FREQUENCY RANGE; TRANSITION METAL DICHALCOGENIDES; TWO-DIMENSIONAL CRYSTALS; TWO-DIMENSIONAL MATERIALS; ULTRASENSITIVE DETECTION;

HYBRID MATERIALS;

DICHALCOGENIDE; GRAPHENE; NANOPARTICLE; QUANTUM DOT; SILICON; TRANSITION ELEMENT; UNCLASSIFIED DRUG; GRAPHITE; NANOMATERIAL;

DIELECTRIC CONSTANT; ELECTRIC CONDUCTIVITY; ELECTRIC FIELD; ELECTROMAGNETIC RADIATION; ELECTRON; ELECTRONICS; FIELD EFFECT TRANSISTOR; HEAT TOLERANCE; INFRARED RADIATION; LIGHT ABSORPTION; LIGHT INTENSITY; OPTICS; PHONON; PHOTOCHEMISTRY; PHOTODETECTOR; PHOTON; PRIORITY JOURNAL; RADIATION FIELD; REVIEW; SEMICONDUCTOR; TEMPERATURE DEPENDENCE; TERAHERTZ RADIATION; CHEMISTRY; DEVICES; EQUIPMENT DESIGN; LIGHT;

ELECTRONICS; EQUIPMENT DESIGN; GRAPHITE; LIGHT; NANOSTRUCTURES; OPTICS AND PHOTONICS; SEMICONDUCTORS;

EID: 84910118830     PISSN: 17483387     EISSN: 17483395     Source Type: Journal    
DOI: 10.1038/nnano.2014.215     Document Type: Review

References (157)

1. Bonaccorso, F., Sun, Z., Hasan, T. & Ferrari, A. C. Graphene photonics and optoelectronics. Nature Photon. 4, 611-622 (2010).
2. Ferrari, A. C. et al. Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems. Nanoscale (in the press).
3. Sun, Z. et al. Graphene mode-locked ultrafast laser. ACS Nano 4, 803-810 (2010).
4. Koppens, F. H. L., Chang, D. E. & Garcia de Abajo, F. J. Graphene plasmonics: A platform for strong light-matter interactions. Nano Lett. 11, 3370-3377 (2011).
5. Grigorenko, A. N., Polini, M. & Novoselov, K. S. Graphene plasmonics. Nature Photon. 6, 749-758 (2012).
6. Kim, K. S. et al. Large-scale pattern growth of graphene films for stretchable transparent electrodes. Nature 457, 706-710 (2009).
7. Pospischil, A., Furchi, M. M. & Mueller, T. Solar-energy conversion and light emission in an atomic monolayer p-n diode. Nature Nanotech. 9, 257-261 (2014).
8. Baugher, B. W. H., Churchill, H. O. H., Yang, Y. & Jarillo-Herrero, P. Optoelectronic devices based on electrically tunable p-n diodes in a monolayer dichalcogenide. Nature Nanotech. 9, 262-267 (2014).
9. Liu, M. et al. A graphene-based broadband optical modulator. Nature 474, 64-67 (2011).
10. Low, T. & Avouris, P. Graphene plasmonics for terahertz to mid-infrared applications. ACS Nano 8, 1086-1101 (2014).
11. Dawlaty, J. M., Shivaraman, S., Chandrashekhar, M., Rana, F. & Spencer, M. G. Measurement of ultrafast carrier dynamics in epitaxial graphene. Appl. Phys. Lett. 92, 42116 (2008).
12. Brida, D. et al. Ultrafast collinear scattering and carrier multiplication in graphene. Nature Commun. 4, 1987 (2013).
13. Dawlaty, J. M. et al. Measurement of the optical absorption spectra of epitaxial graphene from terahertz to visible. Appl. Phys. Lett. 93, 131905 (2008).
14. Nair, R. R. et al. Fine structure constant defines visual transparency of graphene. Science 320, 1308 (2008).
15. Kuzmenko, A. B., van Heumen, E., Carbone, F. & van der Marel, D. Universal optical conductance of graphite. Phys. Rev. Lett. 100, 117401 (2008).
16. Li, Z. Q. et al. Dirac charge dynamics in graphene by infrared spectroscopy. Nature Phys. 4, 532-535 (2008).
17. Wang, F. et al. Gate-variable optical transitions in graphene. Science 320, 206-209 (2008).
18. Xia, F., Mueller, T., Lin, Y.-M., Valdes-Garcia, A. & Avouris, P. Ultrafast graphene photodetector. Nature Nanotech. 4, 839-843 (2009).
19. Mueller, T., Xia, F. & Avouris, P. Graphene photodetectors for high-speed optical communications. Nature Photon. 4, 297-301 (2010).
20. Gan, X. et al. Chip-integrated ultrafast graphene photodetector with high responsivity. Nature Photon. 7, 883-887 (2013).
21. Pospischil, A. et al. CMOS-compatible graphene photodetector covering all optical communication bands. Nature Photon. 7, 892-896 (2013).
22. Wang, X., Cheng, Z., Xu, K., Tsang, H. K. & Xu, J. High-responsivity graphene/silicon-heterostructure waveguide photodetectors. Nature Photon. 7, 888-891 (2013).
23. Novoselov, K. S. & Castro Neto, A. H. Two-dimensional crystals-based heterostructures: materials with tailored properties. Phys. Scripta T146, 014006 (2012).
24. Bonaccorso, F. et al. Production and processing of graphene and 2D crystals. Mater. Today 15, 564-589 (December, 2012).
25. Wilson, J. A. & Yoffe, A. D. The transition metal dichalcogenides discussion and interpretation of the observed optical, electrical and structural properties. Adv. Phys. 18, 193-335 (1969).
26. Peters, E. C., Lee, E. J. H., Burghard, M. & Kern, K. Gate dependent photocurrents at a graphene p-n junction. Appl. Phys. Lett. 97, 193102 (2010).
27. Rao, G., Freitag, M., Chiu, H.-Y., Sundaram, R. S. & Avouris, P. Raman and photocurrent imaging of electrical stress-induced p-n junctions in graphene. ACS Nano 5, 5848-5854 (2011).
28. Mueller, T., Xia, F., Freitag, M., Tsang, J. & Avouris, P. Role of contacts in graphene transistors: A scanning photocurrent study. Phys. Rev. B 79, 245430 (2009).
29. Farmer, D. B. et al. Chemical doping and electron-hole conduction asymmetry in graphene devices. Nano Lett. 9, 388-392 (2009).
30. Lemme, M. C. et al. Gate-Activated photoresponse in a graphene p-n junction. Nano Lett. 11, 4134-4137 (2011).
31. Freitag, M., Low, T., Xia, F. & Avouris, P. Photoconductivity of biased graphene. Nature Photon. 7, 53-59 (2012).
32. Kim, R., Perebeinos, V. & Avouris, P. Relaxation of optically excited carriers in graphene. Phys. Rev. B 84, 075449 (2011).
33. Malic, E., Winzer, T., Bobkin, E. & Knorr, A. Microscopic theory of absorption and ultrafast many-particle kinetics in graphene. Phys. Rev. B 84, 205406 (2011).
34. Tomadin, A., Brida, D., Cerullo, G., Ferrari, A. C. & Polini, M. Nonequilibrium dynamics of photoexcited electrons in graphene: Collinear scattering, Auger processes, and the impact of screening. Phys. Rev. B 88, 035430 (2013).
35. Winzer, T., Knorr, A. & Malic, E. Carrier multiplication in graphene. Nano Lett. 10, 4839-4843 (2010).
36. Xu, X., Gabor, N. M., Alden, J. S., van der Zande, A. M. & McEuen, P. L. Photo-Thermoelectric effect at a graphene interface junction. Nano Lett. 10, 562-566 (2010).
37. Gabor, N. M. et al. Hot carrier-Assisted intrinsic photoresponse in graphene. Science 334, 648-52 (2011).
38. Song, J. C. W., Rudner, M. S., Marcus, C. M. & Levitov, L. S. Hot carrier transport and photocurrent response in graphene. Nano Lett. 11, 4688-4692 (2011).
39. Sun, D. et al. Ultrafast hot-carrier-dominated photocurrent in graphene. Nature Nanotech. 7, 114-118 (2012).
40. Kotov, V. N., Uchoa, B., Pereira, V. M., Guinea, F. & Castro Neto, A. H. Electron-electron interactions in graphene: current status and perspectives. Rev. Mod. Phys. 84, 1067-1125 (2012).
41. Tielrooij, K. J. et al. Photoexcitation cascade and multiple hot-carrier generation in graphene. Nature Phys. 9, 248-252 (2013).
42. Song, J. C. W., Tielrooij, K. J., Koppens, F. H. L. & Levitov, L. S. Photoexcited carrier dynamics and impact-excitation cascade in graphene. Phys. Rev. B 87, 155429 (2013).
43. Gierz, I. et al. Snapshots of non-equilibrium Dirac carrier distributions in graphene. Nature Mater. 12, 1119-1124 (2013).
44. Johannsen, J. C. et al. Direct view of hot carrier dynamics in graphene. Phys. Rev. Lett. 111, 027403 (2013).
45. Piscanec, S., Lazzeri, M., Mauri, F., Ferrari, A. C. & Robertson, J. Kohn anomalies and electron-phonon interactions in graphite. Phys. Rev. Lett. 93, 185503 (2004).
46. Lazzeri, M., Piscanec, S., Mauri, F., Ferrari, A. & Robertson, J. Electron transport and hot phonons in carbon nanotubes. Phys. Rev. Lett. 95, 236802 (2005).
47. Bistritzer, R. & MacDonald, A. H. Electronic cooling in graphene. Phys. Rev Lett. 102, 206410 (2009).
48. Tse, W.-K. & Das Sarma, S. Energy relaxation of hot Dirac fermions in graphene. Phys. Rev. B 79, 235406 (2009).
49. Song, J. C. W., Reizer, M. Y. & Levitov, L. S. Disorder-Assisted electron-phonon scattering and cooling pathways in graphene. Phys. Rev. Lett. 109, 106602 (2012).
50. Graham, M. W., Shi, S-F., Ralph, D. C., Park, J. & McEuen, P. L. Photocurrent measurements of supercollision cooling in graphene. Nature Phys. 9, 103-108 (2012).
51. Betz, A. C. et al. Supercollision cooling in undoped graphene. Nature Phys. 9, 109-112 (2012).
52. Freitag, M., Low, T. & Avouris, P. Increased responsivity of suspended graphene photodetectors. Nano Lett. 13, 1644-1648 (2013).
53. Ashcroft, N. W. & Mermin, N. D. Solid State Physics 848 (Cengage Learning, 1976).
54. Castro Neto, A. H., Guinea, F., Peres, N. M. R., Novoselov, K. S. & Geim, A. K. The electronic properties of graphene. Rev. Mod. Phys. 81, 109-162 (2009).
55. Soref, R. A. Silicon-based optoelectronics. Proc. IEEE 81, 1687-1706 (1993).
56. Richards, P. L. Bolometers for infrared and millimeter waves. J. Appl. Phys. 76, 1 (1994).
57. Rose, A. Concepts in Photoconductivity and Allied Problems (Krieger, 1978).
58. Dyakonov, M. & Shur, M. Shallow water analogy for a ballistic field effect transistor: New mechanism of plasma wave generation by dc current. Phys. Rev. Lett. 71, 2465-2468 (1993).
59. Dyakonov, M. & Shur, M. Detection, mixing, and frequency multiplication of terahertz radiation by two-dimensional electronic fluid. IEEE Trans. Electron Dev. 43, 380-387 (1996).
60. Giuliani, G. F. & Vignale, G. Quantum Theory of the Electron Liquid (Cambridge Univ. Press, 2005).
61. Tomadin, A. & Polini, M. Theory of the plasma-wave photoresponse of a gated graphene sheet. Phys. Rev. B 88, 205426 (2013).
62. Vicarelli, L. et al. Graphene field-effect transistors as room-Temperature terahertz detectors. Nature Mater. 11, 865-871 (2012).
63. Spirito, D. et al. High performance bilayer-graphene terahertz detectors. Appl. Phys. Lett. 104, 061111 (2014).
64. Park, J., Ahn, Y. H. & Ruiz-Vargas, C. Imaging of photocurrent generation and collection in single-layer graphene. Nano Lett. 9, 1742-1746 (2009).
65. Lee, E. J. H., Balasubramanian, K., Weitz, R. T., Burghard, M. & Kern, K. Contact and edge effects in graphene devices. Nature Nanotech. 3, 486-490 (2008).
66. Xia, F. et al. Photocurrent imaging and efficient photon detection in a graphene transistor. Nano Lett. 9, 1039-1044 (2009).
67. Giovannetti, G. et al. Doping graphene with metal contacts. Phys. Rev. Lett. 101, 26803 (2008).
68. Huard, B., Stander, N., Sulpizio, J. & Goldhaber-Gordon, D. Evidence of the role of contacts on the observed electron-hole asymmetry in graphene. Phys. Rev. B 78, 121402 (2008).
69. Urich, A. et al. Silver nanoisland enhanced Raman interaction in graphene. Appl. Phys. Lett. 101, 153113 (2012).
70. Withers, F., Bointon, T. H., Craciun, M. F. & Russo, S. All-graphene photodetectors. ACS Nano 7, 5052-5057 (2013).
71. Prechtel, L. et al. Time-resolved ultrafast photocurrents and terahertz generation in freely suspended graphene. Nature Commun. 3, 646 (2012).
72. Freitag, M., Low, T. & Avouris, P. Increased responsivity of suspended graphene photodetectors. Nano Lett. 13, 1644-1648 (2013).
73. Echtermeyer, T. J. et al. Photothermoelectric and photoelectric contributions to light detection in metal-graphene-metal photodetectors. Nano Lett. 14, 3733-3742 (2014).
74. Urich, A., Unterrainer, K. & Mueller, T. Intrinsic response time of graphene photodetectors. Nano Lett. 11, 2804-2808 (2011).
75. Furchi, M. et al. Microcavity-integrated graphene photodetector. Nano Lett. 12, 2773-2777 (2012).
76. Engel, M. et al. Light-matter interaction in a microcavity-controlled graphene transistor. Nature Commun. 3, 906 (2012).
77. Shiue, R., Gan, X., Gao, Y., Li, L. & Yao, X. Enhanced photodetection in graphene-integrated photonic crystal cavity. Appl. Phys. Lett. 1, 1-11 (2013).
78. Liu, J. et al. High-performance, tensile-strained Ge p-i-n photodetectors on a Si platform. Appl. Phys. Lett. 87, 103501 (2005).
79. Su, S. et al. GeSn p-i-n photodetector for all telecommunication bands detection. Opt. Express 19, 6400-6405 (2011).
80. Schedin, F. Surface-enhanced Raman spectroscopy of graphene. ACS Nano 4, 5617-5626 (2010).
81. Mertens, J. et al. Controlling subnanometer gaps in plasmonic dimers using graphene. Nano Lett. 13, 5033-5038 (2013).
82. Echtermeyer, T. J. et al. Strong plasmonic enhancement of photovoltage in graphene. Nature Commun. 2, 458 (2011).
83. Liu, Y. et al. Plasmon resonance enhanced multicolour photodetection by graphene. Nature Commun. 2, 579 (2011).
84. Jablan, M., Soljacic, M. & Buljan, H. Plasmons in graphene: Fundamental properties and potential applications. Proc. IEEE 101, 1689-1704 (2013).
85. Thongrattanasiri, S., Koppens, F. H. L. & Garcia de Abajo, F. J. Complete optical absorption in periodically patterned graphene. Phys. Rev. Lett. 108, 047401 (2012).
86. Freitag, M. et al. Photocurrent in graphene harnessed by tunable intrinsic plasmons. Nature Commun. 4, 1951 (2013).
87. Chen, C.-C., Aykol, M., Chang, C.-C., Levi, A. F. J. & Cronin, S. B. Graphene-silicon Schottky diodes. Nano Lett. 11, 1863-1867 (2011).
88. Li, X. et al. Graphene-on-silicon Schottky junction solar cells. Adv. Mater. 22, 2743-2748 (2010).
89. Miao, X. et al. High efficiency graphene solar cells by chemical doping. Nano Lett. 12, 2745-2750 (2012).
90. An, X., Liu, F., Jung, Y. J. & Kar, S. Tunable graphene-silicon heterojunctions for ultrasensitive photodetection. Nano Lett. 13, 909-916 (2013).
91. Tongay, S., Schumann, T. & Hebard, A. F. Graphite based Schottky diodes formed on Si, GaAs, and 4H-SiC substrates. Appl. Phys. Lett. 95, 222103 (2009).
92. Tongay, S. et al. Rectification at graphene-semiconductor interfaces: Zero-gap semiconductor-based diodes. Phys. Rev. X 2, 011002 (2012).
93. Amirmazlaghani, M., Raissi, F., Habibpour, O., Vukusic, J. & Stake, J. Graphene-Si Schottky IR detector. IEEE J. Quantum Electron. 49, 589-594 (2013).
94. Yan, J. et al. Dual-gated bilayer graphene hot-electron bolometer. Nature Nanotech. 7, 472-478 (2012).
95. Tan, Y.-W., Zhang, Y., Stormer, H. L. & Kim, P. Temperature dependent electron transport in graphene. Eur. Phys. J. Spec. Top. 148, 15-18 (2007).
96. Oostinga, J. B., Heersche, H. B., Liu, X., Morpurgo, A. F. & Vandersypen, L. M. K. Gate-induced insulating state in bilayer graphene devices. Nature Mater. 7, 151-157 (2008).
97. Xia, F., Farmer, D. B., Lin, Y-M. & Avouris, P. Graphene field-effect transistors with high on/off current ratio and large transport band gap at room temperature. Nano Lett. 10, 715-718 (2010).
98. Viljas, J. K. & Heikkila, T. T. Electron-phonon heat transfer in monolayer and bilayer graphene. Phys. Rev. B 81, 245404 (2010).
99. Betz, A. C. et al. Hot electron cooling by acoustic phonons in graphene. Phys. Rev. Lett. 109, 056805 (2012).
100. Han, Q. et al. Highly sensitive hot electron bolometer based on disordered graphene. Sci. Rep. 3, 3533 (2013).
101. Vora, H., Kumaravadivel, P., Nielsen, B. & Du, X. Bolometric response in graphene based superconducting tunnel junctions. Appl. Phys. Lett. 100, 153507 (2012).
102. Du, X., Prober, D. E., Vora, H. & Mckitterick, C. B. Graphene-based bolometers. Graphene 2D Mater. 1, 1-22 (2014).
103. Ryzhii, V. The theory of quantum-dot infrared phototransistors. Semicond. Sci. Technol. 11, 759-765 (1996).
104. Rowe, M. A. et al. Single-photon detection using a quantum dot optically gated field-effect transistor with high internal quantum efficiency. Appl. Phys. Lett. 89, 253505 (2006).
105. Konstantatos, G. et al. Hybrid graphene-quantum dot phototransistors with ultrahigh gain. Nature Nanotech. 7, 363-368 (2012).
106. Sun, Z. et al. Infrared photodetectors based on CVD-grown graphene and PbS quantum dots with ultrahigh responsivity. Adv. Mater. 24, 5878-5883 (2012).
107. Klekachev, A. V. et al. Electron accumulation in graphene by interaction with optically excited quantum dots. Physica E 43, 1046-1049 (2011).
108. Guo, W. et al. Oxygen-Assisted charge transfer between ZnO quantum dots and graphene. Small 9, 3031-3036 (2013).
109. McDonald, S. A. et al. Solution-processed PbS quantum dot infrared photodetectors and photovoltaics. Nature Mater. 4, 138-142 (2005).
110. Konstantatos, G. et al. Ultrasensitive solution-cast quantum dot photodetectors. Nature 442, 180-183 (2006).
111. Bfberl, M., Kovalenko, M. V., Gamerith, S., List, E. J. W. & Heiss, W. Inkjet-printed nanocrystal photodetectors operating up to 3 μm wavelengths. Adv. Mater. 19, 3574-3578 (2007).
112. Chen, S-Y. et al. Biologically inspired graphene-chlorophyll phototransistors with high gain. Carbon 63, 23-29 (2013).
113. Fang, Z. et al. Plasmon-induced doping of graphene. ACS Nano 6, 10222-10228 (2012).
114. Sizov, F. & Rogalski, A. THz detectors. Prog. Quantum Electron. 34, 278-347 (2010).
115. Principi, A., Vignale, G., Carrega, M. & Polini, M. Impact of disorder on Dirac plasmon losses. Phys. Rev. B 88, 121405 (2013).
116. Principi, A., Vignale, G., Carrega, M. & Polini, M. Intrinsic lifetime of Dirac plasmons in graphene. Phys. Rev. B 88, 195405 (2013).
117. Ryzhii, V. & Ryzhii, M. Graphene bilayer field-effect phototransistor for terahertz and infrared detection. Phys. Rev. B 79, 245311 (2009).
118. Ryzhii, V., Satou, A. & Otsuji, T. Plasma waves in two-dimensional electron-hole system in gated graphene heterostructures. J. Appl. Phys. 101, 024509 (2007).
119. Knap, W. et al. Nanometer size field effect transistors for terahertz detectors. Nanotechnology 24, 214002 (2013).
120. Mittendorff, M. et al. Ultrafast graphene-based broadband THz detector. Appl. Phys. Lett. 103, 021113 (2013).
121. Cai, X. et al. Sensitive room-Temperature terahertz detection via photothermoelectric effect in graphene. Preprint at http://arxiv.org/abs/1305.3297 (2013).
122. Fivaz, R., Mooser, E. & Moose, E. Mobility of charge carriers in semiconducting layer structures. Phys. Rev. 163, 743-755 (1967).
123. Frindt, R. F. & Yoffe, A. D. Physical properties of layer structures: Optical properties and photoconductivity of thin crystals of molybdenum disulphide. Proc. R. Soc. A 273, 69-83 (1963).
124. Joensen, P., Frindt, R. F. & Morrison, S. R. Single-layer MoS2. Mater. Res. Bull. 21, 457-461 (1986).
125. Mak, K. F., Lee, C., Hone, J., Shan, J. & Heinz, T. F. Atomically thin MoS2: A new direct-gap semiconductor. Phys. Rev. Lett. 105, 136805 (2010).
126. Splendiani, A. et al. Emerging photoluminescence in monolayer MoS2. Nano Lett. 10, 1271-1275 (2010).
127. Zeng, H., Dai, J., Yao, W., Xiao, D. & Cui, X. Valley polarization in MoS2 monolayers by optical pumping. Nature Nanotech. 7, 490-493 (2012).
128. Yin, Z. et al. Single-layer MoS2 phototransistors. ACS Nano 6, 74-80 (2012).
129. Choi, W. et al. High-detectivity multilayer MoS2 phototransistors with spectral response from ultraviolet to infrared. Adv. Mater. 24, 5832-5836 (2012).
130. Lopez-Sanchez, O., Lembke, D., Kayci, M., Radenovic, A. & Kis, A. Ultrasensitive photodetectors based on monolayer MoS2. Nature Nanotech. 8, 497-501 (2013).
131. Tsai, D.-S. et al. Few-layer MoS2 with high broadband photogain and fast optical switching for use in harsh environments. ACS Nano 7, 3905-3911 (2013).
132. Lee, H. S. et al. MoS nanosheet phototransistors with thickness-modulated optical energy gap. Nano Lett. 12, 3695-700 (2012).
133. Liu, F. et al. High-sensitivity photodetectors based on multilayer GaTe flakes. ACS Nano 8, 752-760 (2014).
134. Ross, J. S. et al. Electrically tunable excitonic light-emitting diodes based on monolayer WSe2 p-n junctions. Nature Nanotech. 9, 268-272 (2014).
135. Hu, P., Wen, Z., Wang, L., Tan, P. & Xiao, K. Synthesis of few-layer GaSe nanosheets for high performance photodetectors. ACS Nano 6, 5988-5994 (2012).
136. Hu, P. et al. Highly responsive ultrathin GaS nanosheet photodetectors on rigid and flexible substrates. Nano Lett. 13, 1649-1654 (2013).
137. Jacobs-Gedrim, R. B. et al. Extraordinary photoresponse in two-dimensional In2Se3 nanosheets. ACS Nano 8, 514-521 (2014).
138. Buscema, M. et al. Fast and broadband photoresponse of few-layer black phosphorus field-effect transistors. Nano Lett. 14, 3347-3352 (2014).
139. Perea-Lopez, N. et al. Photosensor device based on few-layered WS2 films. Adv. Funct. Mater. 23, 5511-5517 (2013).
140. Buscema, M. et al. Large and tunable photothermoelectric effect in single-layer MoS2. Nano Lett. 13, 358-363 (2013).
141. Roy, K. et al. Graphene-MoS2 hybrid structures for multifunctional photoresponsive memory devices. Nature Nanotech. 8, 826-830 (2013).
142. Zhang, W. et al. Ultrahigh-gain photodetectors based on atomically thin graphene-MoS2 heterostructures. Sci. Rep. 4, 3826 (2014).
143. Liu, C-H., Chang, Y., Norris, T. B. & Zhong, Z. Graphene photodetectors with ultra-broadband and high responsivity at room temperature. Nature Nanotech. 9, 273-278 (2014).
144. Britnell, L. et al. Field-effect tunneling transistor based on vertical graphene heterostructures. Science 335, 947-950 (2012).
145. Georgiou, T. et al. Vertical field-effect transistor based on graphene-WS2 heterostructures for flexible and transparent electronics. Nature Nanotech. 8, 100-103 (2013).
146. Bernardi, M., Palummo, M. & Grossman, J. C. Extraordinary sunlight absorption and one nanometer thick photovoltaics using two-dimensional monolayer materials. Nano Lett. 13, 3664-3670 (2013).
147. Britnell, L. et al. Strong light-matter interactions in heterostructures of atomically thin films. Science 340, 1311-1314 (2013).
148. Yu, W. J. et al. Highly efficient gate-Tunable photocurrent generation in vertical heterostructures of layered materials. Nature Nanotech. 8, 952-958 (2013).
149. Zhang, B. Y. et al. Broadband high photoresponse from pure monolayer graphene photodetector. Nature Commun. 4, 1811 (2013).
150. Gan, X. et al. Strong enhancement of light-matter interaction in graphene coupled to a photonic crystal nanocavity. Nano Lett. 12, 5626-5631 (2012).
151. Chen, L. & Lipson, M. Ultra-low capacitance and high speed germanium photodetectors on silicon. Opt. Express 17, 7901-7906 (2009).
152. Novack, A. et al. Germanium photodetector with 60 GHz bandwidth using inductive gain peaking. Opt. Express 21, 28387 (2013).
153. Ito, H., Furuta, T., Kodama, S., Watanabe, S. & Ishibashi, T. InP/lnGaAs uni-Travelling-carrier photodiode with 220 GHz bandwidth. Electron. Lett. 35, 1556-1557 (1999).
154. Sukhovatkin, V., Hinds, S., Brzozowski, L. & Sargent, E. H. Colloidal quantum-dot photodetectors exploiting multiexciton generation. Science 324, 1542-1544 (2009).
155. Konstantatos, G., Clifford, J., Levina, L. & Sargent, E. H. Sensitive solution-processed visible-wavelength photodetectors. Nature Photon. 1, 531-534 (2007).
156. Keuleyan, S., Lhuillier, E., Brajuskovic, V. & Guyot-Sionnest, P. Mid-infrared HgTe colloidal quantum dot photodetectors. Nature Photon. 5, 489-493 (2011).
157. Tonouchi, M. Cutting-edge terahertz technology. Nature Photon. 1, 97-105 (2007).