近年來，二維材料因為其獨特的性質而密集地研究，而石墨烯的興起更為下一個世代的電子元件開啟了新的一頁，因其具有高機械強度，高載流子遷移率和高化學活性，然而，由於缺乏能隙的特性，限制了石墨烯的發展，因此過渡金屬二硫化物的出現，提供了新的可能性，並有機會可以取代石墨烯成為新一世代的電子元件，過渡金屬二硫化物的優點在於過渡金屬和硫屬元素原子的多樣性組合進而表現出各種不同的性質。而在這些過渡金屬二硫化物中，二硫化鉑是其中最有前景材料之一，因其具有高載流子遷移率，化學活性和穩定性的，而在2015年，有研究團隊透過直接硒化鉑金屬，進而成功製備了二硫化鉑，並在亞甲藍的光催化降解的實驗中，表現出高化學活性，此外，相對於其他的二維材料，合成溫度較低，只有270℃，給柔性電子產品及半導體製程工業提供了新的選項。
根據此研究團隊的成果，我們使用了類似的合成方法，但是引進了電漿輔助的爐管系統，由此可以降低製成的溫度並同時能保持其品質，透過電漿輔助系統，合成溫度可以達到100℃，此為目前成長溫度最低的二維材料，除了合成溫度低之外，透過場效電晶體和其他方式來研究二硒化鉑的性質，由於其對於層數的相當敏感，層與層之間的強凡得瓦力，會有從金屬性轉變為半導體性的行為。隨著厚度的增加，通道效應會變弱，進而證實半導體到金屬的轉變。利用這種獨特的性質，製作出全二硒化鉑電晶體以消除蕭特基能障。雖然載子遷移率和開/關比不如一般的金屬電極，但提供了新的選擇和改進的空間。除了電性研究之外，也對於二硒化鉑的光學性質進行研究，發現其有很寬的吸收範圍並有著很好的響應，並且因為製程溫度低，可以適用於柔性基板，並且它可以在高曲率半徑和彎曲週期測試下，保持其良好的光響應，另一方面，基於理論計算，二硒化鉑有著高化學感測性，藉此，我們也展現了其對二氧化氮的高靈敏度和響應，透過優化製成溫度和厚度，可以在1 ppm NO2氣氛下，響應可達600％，並有著很高的穩定性。最後，我們以實驗證明了二硒化鉑具有高席貝克係數和導電率性質，並且根據理論計算，應力對於其熱電性質有很大的影響，藉由調整應變量，最高功率因數可以達到300 μW/mK2以上。

Two-dimensional materials have been intensively studied due to their unique properties. The rise of graphene gives the new opportunity for the next generation of electronics with high mechanical strength, carrier mobility, and chemical activity. However, the lack of band gap limits the development of graphene and the transition metal dichalcogenides (TMDCs become the new candidates to replace graphene. The advantages of TMDCs are that they exhibit diverse properties with various combination of transition metal and chalcogen atoms. Among these TMDCs, PtSe2 is one of the promising material which owns high carrier mobility, chemical activity, and air stability. In 2015, PtSe2 was successfully fabricated through directly selenization Pt thin film and PtSe2 exhibited high chemical activity in photocatalytic degradation of methylene blue. Furthermore, the synthesis temperature is relatively lower than other TMDCs which can reach 270 oC providing the opportunity for flexible electronics.
In this work, we utilized a similar method but induced the plasma-assisted furnace system which can reduce the formation temperature and keep the similar quality. Through this system, the growth temperature can reach 100 oC which could be the lowest growth temperature for TMDCs. In addition to the low formation temperature, the electrical property of PtSe2 was also investigated through field effect transistor and other application. According to the high sensitivity to the number of layers, PtSe2 would transit from metallic to semiconducting behavior when the thickness decreases and it is contributed from the strong van der Waal forces between layers. Based on this unique property, the all PtSe2 transistor was fabricated to eliminate the Schottky barrier between PtSe2 and electrode. Although the mobility and on/off ratio is not as good as metal contact, it provides the new choice and potential for next generation transistor. In addition to electrical performance, the optical property of PtSe2 was also investigated and PtSe2 shows a wide absorption spectrum. Due to the low fabrication temperature ans wide absorption spectrum, the flexible optoelectronics was demonstrated and it can maintain good photo-response under small bending radius and a large number of bending cycles. On the other hand, we also demonstrated the high sensitivity and response of PtSe2 to NO2. Through optimized the growth temperature and thickness, the best condition can be obtained and the response can reach over 500 % under 1 ppm NO2 atmosphere with good stability which is compatible with other works. Finally, we demonstrated the thermoelectric property of PtSe2 with high Seebeck coefficient and electrical conductivity. Through theoretical calculation, the stress influences the band diagram significantly. By tuning the amount of strain, the highest power factor can reach over 300 uW/mK2.

1. Geim, A. K., Graphene: Status and Prospects. Science 2009, 324 (5934), 1530-1534.
2. GEIM, A. K.; NOVOSELOV, K. S., The rise of graphene. In Nanoscience and Technology, pp 11-19.
3. Bolotin, K. I.; Sikes, K. J.; Jiang, Z.; Klima, M.; Fudenberg, G.; Hone, J.; Kim, P.; Stormer, H. L., Ultrahigh electron mobility in suspended graphene. Solid State Communications 2008, 146 (9), 351-355.
4. Lee, C.; Wei, X.; Kysar, J. W.; Hone, J., Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene. Science 2008, 321 (5887), 385-388.
5. Fowler, J. D.; Allen, M. J.; Tung, V. C.; Yang, Y.; Kaner, R. B.; Weiller, B. H., Practical Chemical Sensors from Chemically Derived Graphene. ACS Nano 2009, 3 (2), 301-306.
6. Shao, Y.; Wang, J.; Wu, H.; Liu, J.; Aksay, I. A.; Lin, Y., Graphene Based Electrochemical Sensors and Biosensors: A Review. Electroanalysis 2010, 22 (10), 1027-1036.
7. Vogt, P.; De Padova, P.; Quaresima, C.; Avila, J.; Frantzeskakis, E.; Asensio, M. C.; Resta, A.; Ealet, B.; Le Lay, G., Silicene: Compelling Experimental Evidence for Graphenelike Two-Dimensional Silicon. Physical Review Letters 2012, 108 (15), 155501.
8. Ni, Z.; Liu, Q.; Tang, K.; Zheng, J.; Zhou, J.; Qin, R.; Gao, Z.; Yu, D.; Lu, J., Tunable Bandgap in Silicene and Germanene. Nano Letters 2012, 12 (1), 113-118.
9. Liu, H.; Neal, A. T.; Zhu, Z.; Luo, Z.; Xu, X.; Tománek, D.; Ye, P. D., Phosphorene: An Unexplored 2D Semiconductor with a High Hole Mobility. ACS Nano 2014, 8 (4), 4033-4041.
10. Chhowalla, M.; Shin, H. S.; Eda, G.; Li, L.-J.; Loh, K. P.; Zhang, H., The chemistry of two-dimensional layered transition metal dichalcogenide nanosheets. Nat Chem 2013, 5 (4), 263-275.
11. Wang, Q. H.; Kalantar-Zadeh, K.; Kis, A.; Coleman, J. N.; Strano, M. S., Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. Nature Nanotechnology 2012, 7, 699.
12. Coleman, J. N.; Lotya, M.; O’Neill, A.; Bergin, S. D.; King, P. J.; Khan, U.; Young, K.; Gaucher, A.; De, S.; Smith, R. J.; Shvets, I. V.; Arora, S. K.; Stanton, G.; Kim, H.-Y.; Lee, K.; Kim, G. T.; Duesberg, G. S.; Hallam, T.; Boland, J. J.; Wang, J. J.; Donegan, J. F.; Grunlan, J. C.; Moriarty, G.; Shmeliov, A.; Nicholls, R. J.; Perkins, J. M.; Grieveson, E. M.; Theuwissen, K.; McComb, D. W.; Nellist, P. D.; Nicolosi, V., Two-Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials. Science 2011, 331 (6017), 568-571.
13. Radisavljevic, B.; Radenovic, A.; Brivio, J.; Giacometti, V.; Kis, A., Single-layer MoS2 transistors. Nature Nanotechnology 2011, 6, 147.
14. Py, M. A.; Haering, R. R., Structural destabilization induced by lithium intercalation in MoS2 and related compounds. Canadian Journal of Physics 1983, 61 (1), 76-84.
15. Ma, Y.; Liu, B.; Zhang, A.; Chen, L.; Fathi, M.; Shen, C.; Abbas, A. N.; Ge, M.; Mecklenburg, M.; Zhou, C., Reversible Semiconducting-to-Metallic Phase Transition in Chemical Vapor Deposition Grown Monolayer WSe2 and Applications for Devices. ACS Nano 2015, 9 (7), 7383-7391.
16. Kappera, R.; Voiry, D.; Yalcin, S. E.; Branch, B.; Gupta, G.; Mohite, A. D.; Chhowalla, M., Phase-engineered low-resistance contacts for ultrathin MoS2 transistors. Nat Mater 2014, 13 (12), 1128-1134.
17. Zhu, X.; Li, D.; Liang, X.; Lu, W. D., Ionic modulation and ionic coupling effects in MoS2 devices for neuromorphic computing. Nature Materials 2019, 18 (2), 141-148.
18. Yun, W. S.; Han, S. W.; Hong, S. C.; Kim, I. G.; Lee, J. D., Thickness and strain effects on electronic structures of transition metal dichalcogenides: 2H-$M{X}_{2}$ semiconductors ($M$ $=$ Mo, W; $X$ $=$ S, Se, Te). Physical Review B 2012, 85 (3), 033305.
19. Mak, K. F.; Lee, C.; Hone, J.; Shan, J.; Heinz, T. F., Atomically Thin ${\mathrm{MoS}}_{2}$: A New Direct-Gap Semiconductor. Physical Review Letters 2010, 105 (13), 136805.
20. Eda, G.; Yamaguchi, H.; Voiry, D.; Fujita, T.; Chen, M.; Chhowalla, M., Photoluminescence from Chemically Exfoliated MoS2. Nano Letters 2011, 11 (12), 5111-5116.
21. Ramasubramaniam, A., Large excitonic effects in monolayers of molybdenum and tungsten dichalcogenides. Physical Review B 2012, 86 (11), 115409.
22. Verble, J. L.; Wieting, T. J., Lattice Mode Degeneracy in Mo${\mathrm{S}}_{2}$ and Other Layer Compounds. Physical Review Letters 1970, 25 (6), 362-365.
23. Zhao, W.; Ghorannevis, Z.; Amara, K. K.; Pang, J. R.; Toh, M.; Zhang, X.; Kloc, C.; Tan, P. H.; Eda, G., Lattice dynamics in mono- and few-layer sheets of WS2 and WSe2. Nanoscale 2013, 5 (20), 9677-9683.
24. Wieting, T. J.; Verble, J. L., Infrared and Raman Studies of Long-Wavelength Optical Phonons in Hexagonal Mo${\mathrm{S}}_{2}$. Physical Review B 1971, 3 (12), 4286-4292.
25. Lee, C.; Yan, H.; Brus, L. E.; Heinz, T. F.; Hone, J.; Ryu, S., Anomalous Lattice Vibrations of Single- and Few-Layer MoS2. ACS Nano 2010, 4 (5), 2695-2700.
26. Molina-Sánchez, A.; Wirtz, L., Phonons in single-layer and few-layer MoS${}_{2}$ and WS${}_{2}$. Physical Review B 2011, 84 (15), 155413.
27. Brent, J. R.; Savjani, N.; O'Brien, P., Synthetic approaches to two-dimensional transition metal dichalcogenide nanosheets. Progress in Materials Science 2017, 89, 411-478.
28. Zeng, Z.; Yin, Z.; Huang, X.; Li, H.; He, Q.; Lu, G.; Boey, F.; Zhang, H., Single-Layer Semiconducting Nanosheets: High-Yield Preparation and Device Fabrication. Angewandte Chemie 2011, 123 (47), 11289-11293.
29. Lee, Y.-H.; Zhang, X.-Q.; Zhang, W.; Chang, M.-T.; Lin, C.-T.; Chang, K.-D.; Yu, Y.-C.; Wang, J. T.-W.; Chang, C.-S.; Li, L.-J.; Lin, T.-W., Synthesis of Large-Area MoS2 Atomic Layers with Chemical Vapor Deposition. Advanced Materials 2012, 24 (17), 2320-2325.
30. Lin, Y.-C.; Zhang, W.; Huang, J.-K.; Liu, K.-K.; Lee, Y.-H.; Liang, C.-T.; Chu, C.-W.; Li, L.-J., Wafer-scale MoS2 thin layers prepared by MoO3 sulfurization. Nanoscale 2012, 4 (20), 6637-6641.
31. Tan, L. K.; Liu, B.; Teng, J. H.; Guo, S.; Low, H. Y.; Loh, K. P., Atomic layer deposition of a MoS2 film. Nanoscale 2014, 6 (18), 10584-10588.
32. Li, W.-J.; Shi, E.-W.; Ko, J.-M.; Chen, Z.-z.; Ogino, H.; Fukuda, T., Hydrothermal synthesis of MoS2 nanowires. Journal of Crystal Growth 2003, 250 (3), 418-422.
33. Wei, R.; Yang, H.; Du, K.; Fu, W.; Tian, Y.; Yu, Q.; Liu, S.; Li, M.; Zou, G., A facile method to prepare MoS2 with nanoflower-like morphology. Materials Chemistry and Physics 2008, 108 (2), 188-191.
34. Wang, D.; Pan, Z.; Wu, Z.; Wang, Z.; Liu, Z., Hydrothermal synthesis of MoS2 nanoflowers as highly efficient hydrogen evolution reaction catalysts. Journal of Power Sources 2014, 264, 229-234.
35. Hu, Z.; Wang, L.; Zhang, K.; Wang, J.; Cheng, F.; Tao, Z.; Chen, J., MoS2 Nanoflowers with Expanded Interlayers as High-Performance Anodes for Sodium-Ion Batteries. Angewandte Chemie International Edition 2014, 53 (47), 12794-12798.
36. Desai, S. B.; Madhvapathy, S. R.; Sachid, A. B.; Llinas, J. P.; Wang, Q.; Ahn, G. H.; Pitner, G.; Kim, M. J.; Bokor, J.; Hu, C.; Wong, H.-S. P.; Javey, A., MoS₂ transistors with 1-nanometer gate lengths. Science 2016, 354 (6308), 99-102.
37. Chen, M.; Lin, C.; Kai-Hsin, L.; Li, L.; Chen, C.; Cheng-Hao, C.; Ming-Dao, L.; Chen, Y.; Hou, Y.; Lin, C.; Chen, C.; Wu, B.; Wu, C.; Yang, I.; Lee, Y.; Wen-Kuan, Y.; Wang, T.; Yang, F.; Hu, C. In Hybrid Si/TMD 2D electronic double channels fabricated using solid CVD few-layer-MoS2 stacking for V<inf>th</inf> matching and CMOS-compatible 3DFETs, 2014 IEEE International Electron Devices Meeting, 15-17 Dec. 2014; 2014; pp 33.5.1-33.5.4.
38. Lopez-Sanchez, O.; Lembke, D.; Kayci, M.; Radenovic, A.; Kis, A., Ultrasensitive photodetectors based on monolayer MoS2. Nat Nano 2013, 8 (7), 497-501.
39. Tan, H.; Fan, Y.; Zhou, Y.; Chen, Q.; Xu, W.; Warner, J. H., Ultrathin 2D Photodetectors Utilizing Chemical Vapor Deposition Grown WS2 With Graphene Electrodes. ACS Nano 2016, 10 (8), 7866-7873.
40. Lee, H. S.; Min, S.-W.; Chang, Y.-G.; Park, M. K.; Nam, T.; Kim, H.; Kim, J. H.; Ryu, S.; Im, S., MoS2 Nanosheet Phototransistors with Thickness-Modulated Optical Energy Gap. Nano Letters 2012, 12 (7), 3695-3700.
41. Yin, Z.; Li, H.; Li, H.; Jiang, L.; Shi, Y.; Sun, Y.; Lu, G.; Zhang, Q.; Chen, X.; Zhang, H., Single-Layer MoS2 Phototransistors. ACS Nano 2012, 6 (1), 74-80.
42. Huo, N.; Kang, J.; Wei, Z.; Li, S.-S.; Li, J.; Wei, S.-H., Novel and Enhanced Optoelectronic Performances of Multilayer MoS2–WS2 Heterostructure Transistors. Advanced Functional Materials 2014, 24 (44), 7025-7031.
43. Tsai, M.-L.; Su, S.-H.; Chang, J.-K.; Tsai, D.-S.; Chen, C.-H.; Wu, C.-I.; Li, L.-J.; Chen, L.-J.; He, J.-H., Monolayer MoS2 Heterojunction Solar Cells. ACS Nano 2014, 8 (8), 8317-8322.
44. Gu, X.; Cui, W.; Li, H.; Wu, Z.; Zeng, Z.; Lee, S.-T.; Zhang, H.; Sun, B., A Solution-Processed Hole Extraction Layer Made from Ultrathin MoS2 Nanosheets for Efficient Organic Solar Cells. Advanced Energy Materials 2013, 3 (10), 1262-1268.
45. Late, D. J.; Huang, Y.-K.; Liu, B.; Acharya, J.; Shirodkar, S. N.; Luo, J.; Yan, A.; Charles, D.; Waghmare, U. V.; Dravid, V. P.; Rao, C. N. R., Sensing Behavior of Atomically Thin-Layered MoS2 Transistors. ACS Nano 2013, 7 (6), 4879-4891.
46. Medina, H.; Li, J.-G.; Su, T.-Y.; Lan, Y.-W.; Lee, S.-H.; Chen, C.-W.; Chen, Y.-Z.; Manikandan, A.; Tsai, S.-H.; Navabi, A.; Zhu, X.; Shih, Y.-C.; Lin, W.-S.; Yang, J.-H.; Thomas, S. R.; Wu, B.-W.; Shen, C.-H.; Shieh, J.-M.; Lin, H.-N.; Javey, A.; Wang, K. L.; Chueh, Y.-L., Wafer-Scale Growth of WSe2 Monolayers Toward Phase-Engineered hybrid WOx/WSe2 Films with Sub-ppb NOx Gas Sensing by A Low Temperature Plasma-Assisted Selenization Process. Chemistry of Materials 2016.
47. Cho, S.-Y.; Kim, S. J.; Lee, Y.; Kim, J.-S.; Jung, W.-B.; Yoo, H.-W.; Kim, J.; Jung, H.-T., Highly Enhanced Gas Adsorption Properties in Vertically Aligned MoS2 Layers. ACS Nano 2015, 9 (9), 9314-9321.
48. Jaramillo, T. F.; Jørgensen, K. P.; Bonde, J.; Nielsen, J. H.; Horch, S.; Chorkendorff, I., Identification of Active Edge Sites for Electrochemical H₂ Evolution from MoS₂ Nanocatalysts. Science 2007, 317 (5834), 100-102.
49. Chang, K.; Chen, W., l-Cysteine-Assisted Synthesis of Layered MoS2/Graphene Composites with Excellent Electrochemical Performances for Lithium Ion Batteries. ACS Nano 2011, 5 (6), 4720-4728.
50. Wang, Y.; Li, L.; Yao, W.; Song, S.; Sun, J.; Pan, J.; Ren, X.; Li, C.; Okunishi, E.; Wang, Y.-Q., Monolayer PtSe2, a New Semiconducting Transition-Metal-Dichalcogenide, Epitaxially Grown by Direct Selenization of Pt. Nano letters 2015, 15 (6), 4013-4018.
51. Takeuchi, H.; Wung, A.; Xin, S.; Howe, R. T.; Tsu-Jae, K., Thermal budget limits of quarter-micrometer foundry CMOS for post-processing MEMS devices. IEEE Transactions on Electron Devices 2005, 52 (9), 2081-2086.
52. Sedky, S.; Witvrouw, A.; Bender, H.; Baert, K., Experimental determination of the maximum post-process annealing temperature for standard CMOS wafers. IEEE Transactions on Electron Devices 2001, 48 (2), 377-385.
53. Zhang, W.; Huang, Z.; Zhang, W.; Li, Y., Two-dimensional semiconductors with possible high room temperature mobility. Nano Research 2014, 7 (12), 1731-1737.
54. Zhao, Y.; Qiao, J.; Yu, Z.; Yu, P.; Xu, K.; Lau, S. P.; Zhou, W.; Liu, Z.; Wang, X.; Ji, W.; Chai, Y., High-Electron-Mobility and Air-Stable 2D Layered PtSe2 FETs. Advanced Materials 2017, 29 (5), 1604230-n/a.
55. Singh, A. K.; Mathew, K.; Zhuang, H. L.; Hennig, R. G., Computational Screening of 2D Materials for Photocatalysis. The Journal of Physical Chemistry Letters 2015, 6 (6), 1087-1098.
56. Zhuang, H. L.; Hennig, R. G., Computational Search for Single-Layer Transition-Metal Dichalcogenide Photocatalysts. The Journal of Physical Chemistry C 2013, 117 (40), 20440-20445.
57. Asahi, R.; Morikawa, T.; Ohwaki, T.; Aoki, K.; Taga, Y., Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides. Science 2001, 293 (5528), 269-271.
58. Chia, X.; Adriano, A.; Lazar, P.; Sofer, Z.; Luxa, J.; Pumera, M., Layered Platinum Dichalcogenides (PtS2, PtSe2, and PtTe2) Electrocatalysis: Monotonic Dependence on the Chalcogen Size. Advanced Functional Materials 2016, 26 (24), 4306-4318.
59. Lin, S.; Liu, Y.; Hu, Z.; Lu, W.; Mak, C. H.; Zeng, L.; Zhao, J.; Li, Y.; Yan, F.; Tsang, Y. H.; Zhang, X.; Lau, S. P., Tunable active edge sites in PtSe2 films towards hydrogen evolution reaction. Nano Energy 2017, 42, 26-33.
60. Sajjad, M.; Montes, E.; Singh, N.; Schwingenschlögl, U., Superior Gas Sensing Properties of Monolayer PtSe2. Advanced Materials Interfaces 2017, 4 (5), 1600911.
61. Usui, H.; Kuroki, K.; Nakano, S.; Kudo, K.; Nohara, M., Pudding-Mold-Type Band as an Origin of the Large Seebeck Coefficient Coexisting with Metallic Conductivity in Carrier-Doped FeAs2 and PtSe2. Journal of Electronic Materials 2014, 43 (6), 1656-1661.
62. Zhang, W.; Guo, H. T.; Jiang, J.; Tao, Q. C.; Song, X. J.; Li, H.; Huang, J., Magnetism and magnetocrystalline anisotropy in single-layer PtSe2: Interplay between strain and vacancy. Journal of Applied Physics 2016, 120 (1), 013904.
63. Guo, S.-D., Biaxial strain tuned thermoelectric properties in monolayer PtSe2. Journal of Materials Chemistry C 2016, 4 (39), 9366-9374.
64. Yim, C.; Lee, K.; McEvoy, N.; O’Brien, M.; Riazimehr, S.; Berner, N. C.; Cullen, C. P.; Kotakoski, J.; Meyer, J. C.; Lemme, M. C.; Duesberg, G. S., High-Performance Hybrid Electronic Devices from Layered PtSe2 Films Grown at Low Temperature. ACS Nano 2016, 10 (10), 9550-9558.
65. Usui, H.; Suzuki, K.; Kuroki, K.; Nakano, S.; Kudo, K.; Nohara, M., Large Seebeck effect in electron-doped FeAs${}_{2}$ driven by a quasi-one-dimensional pudding-mold-type band. Physical Review B 2013, 88 (7), 075140.
66. Maria, O. B.; Niall, M.; Carlo, M.; Jian-Yao, Z.; Nina, C. B.; Jani, K.; Kenan, E.; Timothy, J. P.; Jannik, C. M.; Chanyoung, Y.; Mohamed, A.; Toby, H.; John, F. D.; Stefano, S.; Georg, S. D., Raman characterization of platinum diselenide thin films. 2D Materials 2016, 3 (2), 021004.
67. Ali Umar, A.; Md Saad, S. K.; Mat Salleh, M., Scalable Mesoporous Platinum Diselenide Nanosheet Synthesis in Water. ACS Omega 2017, 2 (7), 3325-3332.
68. Wang, Z.; Li, Q.; Besenbacher, F.; Dong, M., Facile Synthesis of Single Crystal PtSe2 Nanosheets for Nanoscale Electronics. Advanced Materials 2016, 28 (46), 10224-10229.
69. Piotrowski, M. J.; Nomiyama, R. K.; Da Silva, J. L. F., Role of van der Waals corrections for the Pt${X}_{2}$ ($X=\text{O}$, S, Se) compounds. Physical Review B 2013, 88 (7), 075421.
70. Kliche, G., Far-infrared and X-ray investigations of the mixed platinum dichalcogenides PtS2−xSex, PtSe2−xTex, and PtS2−xTex. Journal of Solid State Chemistry 1985, 56 (1), 26-31.
71. Li, X.; Cai, W.; An, J.; Kim, S.; Nah, J.; Yang, D.; Piner, R.; Velamakanni, A.; Jung, I.; Tutuc, E.; Banerjee, S. K.; Colombo, L.; Ruoff, R. S., Large-Area Synthesis of High-Quality and Uniform Graphene Films on Copper Foils. Science 2009, 324 (5932), 1312.
72. Li, X.; Zhu, Y.; Cai, W.; Borysiak, M.; Han, B.; Chen, D.; Piner, R. D.; Colombo, L.; Ruoff, R. S., Transfer of Large-Area Graphene Films for High-Performance Transparent Conductive Electrodes. Nano Letters 2009, 9 (12), 4359-4363.
73. Lin, Y.-C.; Zhang, W.; Huang, J.-K.; Liu, K.-K.; Lee, Y.-H.; Liang, C.-T.; Chu, C.-W.; Li, L.-J., Wafer-scale MoS 2 thin layers prepared by MoO 3 sulfurization. Nanoscale 2012, 4 (20), 6637-6641.
74. Xu, Y.; Cheng, C.; Du, S.; Yang, J.; Yu, B.; Luo, J.; Yin, W.; Li, E.; Dong, S.; Ye, P.; Duan, X., Contacts between Two- and Three-Dimensional Materials: Ohmic, Schottky, and p–n Heterojunctions. ACS Nano 2016, 10 (5), 4895-4919.
75. Endo, H.; Sugibuchi, M.; Takahashi, K.; Goto, S.; Sugimura, S.; Hane, K.; Kashiwaba, Y., Schottky ultraviolet photodiode using a ZnO hydrothermally grown single crystal substrate. Applied Physics Letters 2007, 90 (12), 121906.
76. Liu, W.; Kang, J.; Sarkar, D.; Khatami, Y.; Jena, D.; Banerjee, K., Role of Metal Contacts in Designing High-Performance Monolayer n-Type WSe2 Field Effect Transistors. Nano Letters 2013, 13 (5), 1983-1990.
77. Chuang, S.; Battaglia, C.; Azcatl, A.; McDonnell, S.; Kang, J. S.; Yin, X.; Tosun, M.; Kapadia, R.; Fang, H.; Wallace, R. M.; Javey, A., MoS2 P-type Transistors and Diodes Enabled by High Work Function MoOx Contacts. Nano Letters 2014, 14 (3), 1337-1342.
78. Cho, S.; Kim, S.; Kim, J. H.; Zhao, J.; Seok, J.; Keum, D. H.; Baik, J.; Choe, D.-H.; Chang, K. J.; Suenaga, K.; Kim, S. W.; Lee, Y. H.; Yang, H., Phase patterning for ohmic homojunction contact in MoTe₂. Science 2015, 349 (6248), 625-628.
79. Song, S.; Keum, D. H.; Cho, S.; Perello, D.; Kim, Y.; Lee, Y. H., Room Temperature Semiconductor–Metal Transition of MoTe2 Thin Films Engineered by Strain. Nano Letters 2016, 16 (1), 188-193.
80. Lin, Y.-C.; Dumcenco, D. O.; Huang, Y.-S.; Suenaga, K., Atomic mechanism of the semiconducting-to-metallic phase transition in single-layered MoS2. Nat Nano 2014, 9 (5), 391-396.
81. Ambrosi, A.; Sofer, Z.; Pumera, M., 2H [rightward arrow] 1T phase transition and hydrogen evolution activity of MoS2, MoSe2, WS2 and WSe2 strongly depends on the MX2 composition. Chemical Communications 2015, 51 (40), 8450-8453.
82. Vellinga, M. B.; de Jonge, R.; Haas, C., Semiconductor to metal transition in MoTe2. Journal of Solid State Chemistry 1970, 2 (2), 299-302.
83. Joshi, N. V., Photoconductivity : art, science, and technology. 1990.
84. Rose, A., Concepts in photoconductivity and allied problems. Robert E. Krieger: Huntington, New York, 1978.
85. Zeng, L.; Tao, L.; Tang, C.; Zhou, B.; Long, H.; Chai, Y.; Lau, S. P.; Tsang, Y. H., High-responsivity UV-vis photodetector based on transferable ws2 film deposited by magnetron sputtering. Scientific reports 2016, 6.
86. Su, T.-Y.; Medina, H.; Chen, Y.-Z.; Wang, S.-W.; Lee, S.-S.; Shih, Y.-C.; Chen, C.-W.; Kuo, H.-C.; Chuang, F.-C.; Chueh, Y.-L., Phase-Engineered PtSe2-Layered Films by a Plasma-Assisted Selenization Process toward All PtSe2-Based Field Effect Transistor to Highly Sensitive, Flexible, and Wide-Spectrum Photoresponse Photodetectors. Small 2018, 14 (19), 1800032.
87. Zhang, W.; Qin, J.; Huang, Z.; Zhang, W., The mechanism of layer number and strain dependent bandgap of 2D crystal PtSe2. Journal of Applied Physics 2017, 122 (20), 205701.
88. Duy, L. T.; Kim, D.-J.; Trung, T. Q.; Dang, V. Q.; Kim, B.-Y.; Moon, H. K.; Lee, N.-E., High Performance Three-Dimensional Chemical Sensor Platform Using Reduced Graphene Oxide Formed on High Aspect-Ratio Micro-Pillars. Advanced Functional Materials 2015, 25 (6), 883-890.
89. Hassinen, J.; Kauppila, J.; Leiro, J.; Määttänen, A.; Ihalainen, P.; Peltonen, J.; Lukkari, J., Low-cost reduced graphene oxide-based conductometric nitrogen dioxide-sensitive sensor on paper. Analytical and Bioanalytical Chemistry 2013, 405 (11), 3611-3617.
90. Li, J.; Lu, Y.; Ye, Q.; Cinke, M.; Han, J.; Meyyappan, M., Carbon Nanotube Sensors for Gas and Organic Vapor Detection. Nano Letters 2003, 3 (7), 929-933.
91. Zhou, Y.; Liu, G.; Zhu, X.; Guo, Y., Ultrasensitive NO2 gas sensing based on rGO/MoS2 nanocomposite film at low temperature. Sensors and Actuators B: Chemical 2017, 251, 280-290.
92. Kim, C.; Park, J.-C.; Choi, S. Y.; Kim, Y.; Seo, S.-Y.; Park, T.-E.; Kwon, S.-H.; Cho, B.; Ahn, J.-H., Self-Formed Channel Devices Based on Vertically Grown 2D Materials with Large-Surface-Area and Their Potential for Chemical Sensor Applications. Small 2018, 14 (15), 1704116.
93. Wang, J.; Lian, G.; Xu, Z.; Fu, C.; Lin, Z.; Li, L.; Wang, Q.; Cui, D.; Wong, C.-P., Growth of Large-Size SnS Thin Crystals Driven by Oriented Attachment and Applications to Gas Sensors and Photodetectors. ACS Applied Materials & Interfaces 2016, 8 (15), 9545-9551.
94. Cha, J.-H.; Choi, S.-J.; Yu, S.; Kim, I.-D., 2D WS2-edge functionalized multi-channel carbon nanofibers: effect of WS2 edge-abundant structure on room temperature NO2 sensing. Journal of Materials Chemistry A 2017, 5 (18), 8725-8732.
95. Deng, S.; Tjoa, V.; Fan, H. M.; Tan, H. R.; Sayle, D. C.; Olivo, M.; Mhaisalkar, S.; Wei, J.; Sow, C. H., Reduced Graphene Oxide Conjugated Cu2O Nanowire Mesocrystals for High-Performance NO2 Gas Sensor. Journal of the American Chemical Society 2012, 134 (10), 4905-4917.
96. Liu, B.; Chen, L.; Liu, G.; Abbas, A. N.; Fathi, M.; Zhou, C., High-Performance Chemical Sensing Using Schottky-Contacted Chemical Vapor Deposition Grown Monolayer MoS2 Transistors. ACS Nano 2014, 8 (5), 5304-5314.
97. Abbas, A. N.; Liu, B.; Chen, L.; Ma, Y.; Cong, S.; Aroonyadet, N.; Köpf, M.; Nilges, T.; Zhou, C., Black Phosphorus Gas Sensors. ACS Nano 2015, 9 (5), 5618-5624.
98. Kim, Y. H.; Kim, S. J.; Kim, Y.-J.; Shim, Y.-S.; Kim, S. Y.; Hong, B. H.; Jang, H. W., Self-Activated Transparent All-Graphene Gas Sensor with Endurance to Humidity and Mechanical Bending. ACS Nano 2015, 9 (10), 10453-10460.
99. Ko, K. Y.; Song, J.-G.; Kim, Y.; Choi, T.; Shin, S.; Lee, C. W.; Lee, K.; Koo, J.; Lee, H.; Kim, J.; Lee, T.; Park, J.; Kim, H., Improvement of Gas-Sensing Performance of Large-Area Tungsten Disulfide Nanosheets by Surface Functionalization. ACS Nano 2016, 10 (10), 9287-9296.
100. Li, P.; Li, L.; Zeng, X. C., Tuning the electronic properties of monolayer and bilayer PtSe2via strain engineering. Journal of Materials Chemistry C 2016, 4 (15), 3106-3112.
101. Viezbicke, B. D.; Patel, S.; Davis, B. E.; Birnie III, D. P., Evaluation of the Tauc method for optical absorption edge determination: ZnO thin films as a model system. physica status solidi (b) 2015, 252 (8), 1700-1710.
102. Xie, J.; Zhang, D.; Yan, X.-Q.; Ren, M.; Zhao, X.; Liu, F.; Sun, R.; Li, X.; Li, Z.; Chen, S.; Liu, Z.-B.; Tian, J.-G., Optical properties of chemical vapor deposition-grown PtSe2 characterized by spectroscopic ellipsometry. 2D Materials 2019, 6 (3), 035011.
103. Yim, C.; Lee, K.; McEvoy, N.; O'Brien, M.; Riazimehr, S.; Berner, N. C.; Cullen, C. P.; Kotakoski, J.; Meyer, J. C.; Lemme, M. C.; Duesberg, G. S., High-Performance Hybrid Electronic Devices from Layered PtSe2 Films Grown at Low Temperature. Acs Nano 2016, 10 (10), 9550-9558.
104. O'Brien, M.; McEvoy, N.; Motta, C.; Zheng, J. Y.; Berner, N. C.; Kotakoski, J.; Elibol, K.; Pennycook, T. J.; Meyer, J. C.; Yim, C.; Abid, M.; Hallam, T.; Donegan, J. F.; Sanvito, S.; Duesberg, G. S., Raman characterization of platinum diselenide thin films. 2d Materials 2016, 3 (2), 021004.
105. Tauc, J., Optical properties and electronic structure of amorphous Ge and Si. Mater Res Bull 1968, 3 (1), 37-46.
106. Viezbicke, B. D.; Patel, S.; Davis, B. E.; Birnie, D. P., Evaluation of the Tauc method for optical absorption edge determination: ZnO thin films as a model system. Physica Status Solidi B-Basic Solid State Physics 2015, 252 (8), 1700-1710.
107. Kandemir, A.; Akbali, B.; Kahraman, Z.; Badalov, S. V.; Ozcan, M.; Iyikanat, F.; Sahin, H., Structural, electronic and phononic properties of PtSe2: from monolayer to bulk. Semiconductor Science and Technology 2018, 33 (8), 085002.
108. Ciarrocchi, A.; Avsar, A.; Ovchinnikov, D.; Kis, A., Thickness-modulated metal-to-semiconductor transformation in a transition metal dichalcogenide. Nat. Commun. 2018, 9, 919.
109. Zhao, Y. D.; Qiao, J. S.; Yu, Z. H.; Yu, P.; Xu, K.; Lau, S. P.; Zhou, W.; Liu, Z.; Wang, X. R.; Ji, W.; Chai, Y., High-Electron- Mobility and Air-Stable 2D Layered PtSe2 FETs. Adv. Mater. 2017, 29 (5), 1604230.
110. Oh, J. Y.; Lee, J. H.; Han, S. W.; Chae, S. S.; Bae, E. J.; Kang, Y. H.; Choi, W. J.; Cho, S. Y.; Lee, J.-O.; Baik, H. K.; Lee, T. I., Chemically exfoliated transition metal dichalcogenide nanosheet-based wearable thermoelectric generators. Energy & Environmental Science 2016, 9 (5), 1696-1705.
111. Kim, S.; Bark, H.; Nam, S.; Choi, H.; Lee, H., Control of Electrical and Thermal Transport Properties by Hybridization of Two-Dimensional Tungsten Disulfide and Reduced Graphene Oxide for Thermoelectric Applications. ACS Sustainable Chemistry & Engineering 2018, 6 (11), 15487-15493.
112. Piao, M.; Li, C.; Joo, M.-K.; Chu, J.; Wang, X.; Chi, Y.; Zhang, H.; Shi, H., Hydrothermal Synthesis of Stable 1T-WS2 and Single-Walled Carbon Nanotube Hybrid Flexible Thin Films with Enhanced Thermoelectric Performance. Energy Technology 2018, 6 (10), 1921-1928.
113. Piao, M.; Chu, J.; Wang, X.; Chi, Y.; Zhang, H.; Li, C.; Shi, H.; Joo, M.-K., Hydrothermal synthesis of stable metallic 1T phase WS2 nanosheets for thermoelectric application. Nanotechnology 2017, 29 (2), 025705.
114. Huang, H.; Cui, Y.; Li, Q.; Dun, C.; Zhou, W.; Huang, W.; Chen, L.; Hewitt, C. A.; Carroll, D. L., Metallic 1T phase MoS2 nanosheets for high-performance thermoelectric energy harvesting. Nano Energy 2016, 26, 172-179.
115. Li, X.; Wang, T.; Jiang, F.; Liu, J.; Liu, P.; Liu, G.; Xu, J.; Liu, C.; Jiang, Q., Optimizing thermoelectric performance of MoS2 films by spontaneous noble metal nanoparticles decoration. Journal of Alloys and Compounds 2019, 781, 744-750.
116. Li, X.; Liu, C.; Wang, T.; Wang, W.; Wang, X.; Jiang, Q.; Jiang, F.; Xu, J., Preparation of 2D MoSe2/PEDOT:PSS composite and its thermoelectric properties. Materials Research Express 2017, 4 (11), 116410.
117. An, C. J.; Kang, Y. H.; Lee, C.; Cho, S. Y., Preparation of Highly Stable Black Phosphorus by Gold Decoration for High-Performance Thermoelectric Generators. Advanced Functional Materials 2018, 28 (28), 1800532.
118. Jiang, F.; Xiong, J.; Zhou, W.; Liu, C.; Wang, L.; Zhao, F.; Liu, H.; Xu, J., Use of organic solvent-assisted exfoliated MoS2 for optimizing the thermoelectric performance of flexible PEDOT:PSS thin films. Journal of Materials Chemistry A 2016, 4 (14), 5265-5273.
119. Wang, T.; Liu, C.; Jiang, F.; Xu, Z.; Wang, X.; Li, X.; Li, C.; Xu, J.; Yang, X., Solution-processed two-dimensional layered heterostructure thin-film with optimized thermoelectric performance. Physical Chemistry Chemical Physics 2017, 19 (27), 17560-17567.
120. Xu, H.; Zhang, H.; Liu, Y.; Zhang, S.; Sun, Y.; Guo, Z.; Sheng, Y.; Wang, X.; Luo, C.; Wu, X.; Wang, J.; Hu, W.; Xu, Z.; Sun, Q.; Zhou, P.; Shi, J.; Sun, Z.; Zhang, D. W.; Bao, W., Controlled Doping of Wafer-Scale PtSe2 Films for Device Application. Advanced Functional Materials 2019, 29 (4), 1805614.
121. Mishra, S. K.; Satpathy, S.; Jepsen, O., Electronic structure and thermoelectric properties of bismuth telluride and bismuth selenide. J. Phys.: Condens. Matter 1997, 9 (2), 461-470.
122. Pei, Y. Z.; Shi, X. Y.; LaLonde, A.; Wang, H.; Chen, L. D.; Snyder, G. J., Convergence of electronic bands for high performance bulk thermoelectrics. Nature 2011, 473 (7345), 66-69.
123. Zhao, L.-D.; Tan, G.; Hao, S.; He, J.; Pei, Y.; Chi, H.; Wang, H.; Gong, S.; Xu, H.; Dravid, V. P.; Uher, C.; Snyder, G. J.; Wolverton, C.; Kanatzidis, M. G., Ultrahigh power factor and thermoelectric performance in hole-doped single-crystal SnSe. Science 2016, 351 (6269), 141-144.
124. Tang, Y. L.; Gibbs, Z. M.; Agapito, L. A.; Li, G.; Kim, H. S.; Nardelli, M. B.; Curtarolo, S.; Snyder, G. J., Convergence of multi-valley bands as the electronic origin of high thermoelectric performance in CoSb3 skutterudites. Nat. Mater. 2015, 14 (12), 1223-1228.