隨著技術進步，光偵測器在檢測光的特性和強度方面變得更加重要。近年來，全無機鹵化物鈣鈦礦在光偵測器研究中變得特別受關注，因為它具備高量子效率、快速的載流子傳輸和較長的光載流子壽命等優點。這些無機鈣鈦礦對微弱光源十分敏感，在將入射光轉換為可檢測訊號方面反應快速。此外，較長的光載流子壽命能夠提高元件的信噪比，這使得無機鈣鈦礦在長時間曝光的應用中依然表現優異。加上無機鈣鈦礦材料的低成本生產，進一步增強了其研究優勢，使其在各種光電技術的發展中展現出巨大的應用潛力。
在本研究中，使用熱注入法製備CsPbBr1.2I1.8量子點，並利用化學氣相沉積法製備CdS奈米線，兩者形成異質接面，以增強光電偵測器的性能表現。這種組合能促進界面的電荷轉移和激子解離，有助於增強光偵測器的光響應和靈敏度。CsPbBr1.2I1.8量子點和CdS奈米線的異質結構光偵測器在405 nm藍光下以5 V偏壓達到了2.57×10¹⁰ Jones的探測率和1.30×10⁻² A/W的響應率。通過建立II型能帶排列，CsPbBr1.2I1.8量子點和CdS奈米線的結合增強了光檢測器內的電荷分離，減少載子復合，增強可見光檢測性能。

As technology develops, photodetectors are going to have a progressively growing role in detecting and measuring the characteristics and intensity of light. All-inorganic halide perovskites, with their high quantum efficiency, fast carrier transportation, and extended photocarrier lifetimes, have lately become particularly interesting as a possible material for photodetectors. These inorganic perovskites are sensitive to low-light sources because of their remarkable efficiency in transforming incident light into detectable signals. Moreover, their extended photocarrier lifetimes result in increased signal-to-noise ratios and versatility for applications involving long exposure times. Their accessible production costs further enhance their popularity, making them potential contributors to the advancement of several optoelectronic technologies.
The present research investigates the enhanced performance of a photodetector that forms a heterojunction using CsPbBr1.2I1.8 quantum dots (QDs) manufactured using the hot injection technique and CdS nanowires (NWs) prepared by chemical vapor deposition (CVD). This purposeful integration has the potential to improve the device's photoresponse and sensitivity by facilitating efficient charge transfer and exciton dissociation at the heterojunction interface. More specifically, CsPbBr1.2I1.8 QDs photodetectors heterostructured with CdS NWs demonstrate remarkable performance, attaining a responsivity of 1.30×10-2 A/W and a detectivity of 2.57×1010 Jones at 405 nm blue light with 5 V bias. The integration of CsPbBr1.2I1.8 QDs with CdS NWs improves charge separation inside the photodetector, lowering recombination and enhancing visible light detection efficiency by establishing a type II band alignment.

1. Leung, C. K.; Braun, P.; Cuzzocrea, A., AI-Based Sensor Information Fusion for Supporting Deep Supervised Learning. Sensors 2019, 19 (6), pp 1345-1357.
2. Krishnamurthi, R.; Kumar, A.; Gopinathan, D.; Nayyar, A.; Qureshi, B., An Overview of IoT Sensor Data Processing, Fusion, and Analysis Techniques. Sensors 2020, 20 (21), pp 6076-6098.
3. Nasrollahzadeh, M.; Sajadi, S. M.; Sajjadi, M.; Issaabadi, Z., An Introduction to Nanotechnology. In Interface Science and Technology, Elsevier: 2019; Vol. 28, pp 1-27.
4. Feynman, R., There’s Plenty of Room at the Bottom. In Feynman and Computation, CRC Press: 2018; pp 63-76.
5. Drexler, E., Engines of Creation: The Coming Era of Nanotechnology. Anchor: 1987.
6. Biswas, A.; Bayer, I. S.; Biris, A. S.; Wang, T.; Dervishi, E.; Faupel, F., Advances in Top–Down and Bottom–Up Surface Nanofabrication: Techniques, Applications & Future Prospects. Advances in Colloid and Interface Science 2012, 170 (1), pp 2-27.
7. Bhushan, B., Introduction to Nanotechnology. In Springer Handbook of Nanotechnology, Bhushan, B., Ed. Springer Berlin Heidelberg: Berlin, Heidelberg, 2017; pp 1-19.
8. Gandhi, M.; Amreen, K., Emerging Trends in Nanomaterial-Based Biomedical Aspects. Electrochem 2023, 4 (3), pp 365-388.
9. Poh, T.; Ali, N.; Mac Aogáin, M.; Hussain, M.; Setyawati, M.; Ng, K.; Chotirmall, S., Inhaled Nanomaterials and the Respiratory Microbiome: Clinical, Immunological and Toxicological Perspectives. Particle and Fibre Toxicology 2018, 15(1), pp. 1-16.
10. Nozik, A. J., Quantum Dot Solar Cells. Physica E: Low-Dimensional Systems and Nanostructures 2002, 14 (1), pp 115-120.
11. Yang, Y.; Zheng, Y.; Cao, W.; Titov, A.; Hyvonen, J.; Manders, J. R.; Xue, J.; Holloway, P. H.; Qian, L., High-Efficiency Light-Emitting Devices Based on Quantum Dots with Tailored Nanostructures. Nature Photonics 2015, 9 (4), pp 259-266.
12. Clifford, J. P.; Konstantatos, G.; Johnston, K. W.; Hoogland, S.; Levina, L.; Sargent, E. H., Fast, Sensitive and Spectrally Tuneable Colloidal-Quantum-Dot Photodetectors. Nature Nanotechnology 2009, 4 (1), pp 40-44.
13. Bimberg, D.; Ledentsov, N., Quantum Dots: Lasers and Amplifiers. Journal of Physics: Condensed Matter 2003, 15 (24), pp 1063-1076.
14. Kwon, S. G.; Hyeon, T., Formation Mechanisms of Uniform Nanocrystals via Hot-Injection and Heat-Up Methods. Small 2011, 7 (19), pp 2685-2702.
15. LaMer, V. K.; Dinegar, R. H., Theory, Production and Mechanism of Formation of Monodispersed Hydrosols. Journal of the American Chemical Society 1950, 72 (11), pp 4847-4854.
16. Lu, W.; Lieber, C. M., Semiconductor Nanowires. Journal of Physics D: Applied Physics 2006, 39 (21), pp 387-406.
17. Rao, C. N. R.; Satishkumar, B.; Govindaraj, A.; Nath, M., Nanotubes. ChemPhysChem 2001, 2 (2), pp 78-105.
18. Pérez-Juste, J.; Pastoriza-Santos, I.; Liz-Marzán, L. M.; Mulvaney, P., Gold Nanorods: Synthesis, Characterization and Applications. Coordination Chemistry Reviews 2005, 249 (17-18), pp 1870-1901.
19. Massaglia, G.; Quaglio, M., Semiconducting Nanofibers in Photoelectrochemistry. Materials Science in Semiconductor Processing 2018, 73, pp 13-21.
20. Lieber, C. M.; Wang, Z. L., Functional Nanowires. MRS Bulletin 2007, 32 (2), pp 99-108.
21. Wacaser, B. A.; Dick, K. A.; Johansson, J.; Borgström, M. T.; Deppert, K.; Samuelson, L., Preferential Interface Nucleation: An Expansion of the VLS Growth Mechanism for Nanowires. Advanced Materials 2009, 21 (2), pp 153-165.
22. Ge, J.; Li, Y., Selective Atmospheric Pressure Chemical Vapor Deposition Route to CdS Arrays, Nanowires, and Nanocombs. Advanced Functional Materials 2004, 14 (2), pp 157-162.
23. Cao, G.; Liu, D., Template-Based Synthesis of Nanorod, Nanowire, and Nanotube Arrays. Advances in Colloid and Interface Science 2008, 136 (1), pp 45-64.
24. Kuno, M., An Overview of Solution-Based Semiconductor Nanowires: Synthesis and Optical Studies. Physical Chemistry Chemical Physics 2008, 10 (5), pp 620-639.
25. Wagner, a. R.; Ellis, W., Vapor‐Liquid‐Solid Mechanism of Single Crystal Growth. Applied Physics Letters 1964, 4 (5), pp 89-90.
26. Pinion, C. W. Understanding the Vapor-Liquid-Solid and Vapor-Solid-Solid Mechanisms of Si Nanowire Growth to Synthetically Encode Precise Nanoscale Morphology. Doctoral Thesis, University of North Carolina, Chapel Hill, 2017.
27. Dresselhaus, M. S.; Lin, Y.-M.; Rabin, O.; Black, M. R.; Kong, J.; Dresselhaus, G., Nanowires. In Springer Handbook of Nanotechnology, Bhushan, B., Ed. Springer Berlin Heidelberg: Berlin, Heidelberg, 2010; pp 119-167.
28. Bansal, S.; Parkash, K.; Jain, P.; Kumar, S.; Gupta, N.; Singh, A. K., Photodetectors for Security Application. In Nanoelectronic Devices for Hardware and Software Security, CRC Press: 2021; pp 279-300.
29. Li, L.; Ye, S.; Qu, J.; Zhou, F.; Song, J.; Shen, G., Recent Advances in Perovskite Photodetectors for Image Sensing. Small 2021, 17 (18), 2005606.
30. Casalino, M.; Coppola, G.; De La Rue, R. M.; Logan, D. F., State-of-the-Art All-Silicon Sub-Bandgap Photodetectors at Telecom and Datacom Wavelengths. Laser & Photonics Reviews 2016, 10 (6), pp 895-921.
31. Tyagi, D.; Wang, H.; Huang, W.; Hu, L.; Tang, Y.; Guo, Z.; Ouyang, Z.; Zhang, H., Recent Advances in Two-Dimensional-Material-Based Sensing Technology Toward Health and Environmental Monitoring Applications. Nanoscale 2020, 12 (6), pp 3535-3559.
32. Maculan, G.; Sheikh, A. D.; Abdelhady, A. L.; Saidaminov, M. I.; Haque, M. A.; Murali, B.; Alarousu, E.; Mohammed, O. F.; Wu, T.; Bakr, O. M., CH3NH3PbCl3 Single Crystals: Inverse Temperature Crystallization and Visible-Blind UV-Photodetector. The Journal of Physical Chemistry Letters 2015, 6 (19), pp 3781-3786.
33. Huang, X.; Guo, Y.; Liu, Y., Perovskite Photodetectors and Their Application in Artificial Photonic Synapses. Chemical Communications 2021, 57 (87), pp 11429-11442.
34. Petritz, R. L., Theory of Photoconductivity in Semiconductor Films. Physical Review 1956, 104 (6), pp 1508-1516.
35. Konstantatos, G.; Sargent, E. H., PbS Colloidal Quantum Dot Photoconductive Photodetectors: Transport, Traps, and Gain. Applied Physics Letters 2007, 91 (17), pp 3505-3507.
36. Weiss, D. S.; Abkowitz, M., Advances in Organic Photoconductor Technology. Chemical Reviews 2010, 110 (1), pp 479-526.
37. Guan, X.; Yu, X.; Periyanagounder, D.; Benzigar, M. R.; Huang, J.-K.; Lin, C.-H.; Kim, J.; Singh, S.; Hu, L.; Liu, G.; Li, D.; He, J.-H.; Yan, F.; Wang, Q. J.; Wu, T., Recent Progress in Short- to Long-Wave Infrared Photodetection Using 2D Materials and Heterostructures. Advanced Optical Materials 2021, 9 (4), 2001708.
38. Weckler, G. P., Operation of PN Junction Photodetectors in a Photon Flux Integrating Mode. IEEE Journal of Solid-State Circuits 1967, 2 (3), pp 65-73.
39. Dou, L.; Yang, Y.; You, J.; Hong, Z.; Chang, W.-H.; Li, G.; Yang, Y., Solution-Processed Hybrid Perovskite Photodetectors with High Detectivity. Nature Communications 2014, 5 (1), pp 5404-5410.
40. Huang, Y.-T.; Chen, Y.-H.; Ho, Y.-J.; Huang, S.-W.; Chang, Y.-R.; Watanabe, K.; Taniguchi, T.; Chiu, H.-C.; Liang, C.-T.; Sankar, R., High-Performance InSe Transistors with Ohmic Contact Enabled by Nonrectifying Barrier-Type Indium Electrodes. ACS Applied Materials & Interfaces 2018, 10 (39), pp 33450-33456.
41. Wilamowski, B. M., Schottky Diodes with High Breakdown Voltages. Solid-State Electronics 1983, 26 (5), pp 491-493.
42. El-Kareh, B.; Hutter, L. N.; El-Kareh, B.; Hutter, L. N., Rectifying and Ohmic Contacts. In Silicon Analog Components: Device Design, Process Integration, Characterization, and Reliability 2020, pp 113-149.
43. Averine, S.; Chan, Y.; Lam, Y., Evaluation of Schottky Contact Parameters in Metal–Semiconductor–Metal Photodiode Structures. Applied Physics Letters 2000, 77 (2), pp 274-276.
44. Low, J.; Yu, J.; Jaroniec, M.; Wageh, S.; Al-Ghamdi, A. A., Heterojunction Photocatalysts. Advanced Materials 2017, 29 (20), 1601694.
45. Yang, W.; Hu, K.; Teng, F.; Weng, J.; Zhang, Y.; Fang, X., High-Performance Silicon-Compatible Large-Area UV-to-Visible Broadband Photodetector Based on Integrated Lattice-Matched Type II Se/n-Si Heterojunctions. Nano Letters 2018, 18 (8), pp 4697-4703.
46. Kojima, A.; Teshima, K.; Shirai, Y.; Miyasaka, T., Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells. Journal of the American Chemical Society 2009, 131 (17), pp 6050-6051.
47. Etgar, L.; Gao, P.; Xue, Z.; Peng, Q.; Chandiran, A. K.; Liu, B.; Nazeeruddin, M. K.; Grätzel, M., Mesoscopic CH3NH3PbI3/TiO2 Heterojunction Solar Cells. Journal of the American Chemical Society 2012, 134 (42), pp 17396-17399.
48. Protesescu, L.; Yakunin, S.; Bodnarchuk, M. I.; Krieg, F.; Caputo, R.; Hendon, C. H.; Yang, R. X.; Walsh, A.; Kovalenko, M. V., Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, and I): Novel Optoelectronic Materials Showing Bright Emission with Wide Color Gamut. Nano Letters 2015, 15 (6), pp 3692-3696.
49. Wei, Z.; Perumal, A.; Su, R.; Sushant, S.; Xing, J.; Zhang, Q.; Tan, S. T.; Demir, H. V.; Xiong, Q., Solution-Processed Highly Bright and Durable Cesium Lead Halide Perovskite Light-Emitting Diodes. Nanoscale 2016, 8 (42), pp 18021-18026.
50. Ramasamy, P.; Lim, D.-H.; Kim, B.; Lee, S.-H.; Lee, M.-S.; Lee, J.-S., All-Inorganic Cesium Lead Halide Perovskite Nanocrystals for Photodetector Applications. Chemical Communications 2016, 52 (10), pp 2067-2070.
51. Eperon, G. E.; Paternò, G. M.; Sutton, R. J.; Zampetti, A.; Haghighirad, A. A.; Cacialli, F.; Snaith, H. J., Inorganic Caesium Lead Iodide Perovskite Solar Cells. Journal of Materials Chemistry A 2015, 3 (39), pp 19688-19695.
52. Kaczkowski, J.; Płowaś-Korus, I., The Vibrational and Thermodynamic Properties of CsPbI3 Polymorphs: An Improved Description Based on the SCAN Meta-GGA Functional. The Journal of Physical Chemistry Letters 2021, 12 (28), pp 6613-6621.
53. Wang, B.; Novendra, N.; Navrotsky, A., Energetics, Structures, and Phase Transitions of Cubic and Orthorhombic Cesium Lead Iodide (CsPbI3) Polymorphs. Journal of the American Chemical Society 2019, 141 (37), pp 14501-14504.
54. Syah, R.; Davarpanah, A.; Nasution, M. K. M.; Wali, Q.; Ramdan, D.; Albaqami, M. D.; Ouladsmane, M.; Noori, S. M., The Effect of Structural Phase Transitions on Electronic and Optical Properties of CsPbI3 Pure Inorganic Perovskites. Coatings 2021, 11 (10), pp 1173-1185.
55. Wang, K.; Jin, Z.; Liang, L.; Bian, H.; Bai, D.; Wang, H.; Zhang, J.; Wang, Q.; Liu, S., All-inorganic Cesium Lead Iodide Perovskite Solar Cells with Stabilized Efficiency Beyond 15%. Nature Communications 2018, 9 (1), pp 4544-4551.
56. Nedelcu, G.; Protesescu, L.; Yakunin, S.; Bodnarchuk, M. I.; Grotevent, M. J.; Kovalenko, M. V., Fast Anion-Exchange in Highly Luminescent Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, I). Nano Letters 2015, 15 (8), pp 5635-5640.
57. Zhang, K.; Guo, L., Metal Sulphide Semiconductors for Photocatalytic Hydrogen Production. Catalysis Science & Technology 2013, 3 (7), pp 1672-1690.
58. Fadla, M. A.; Bentria, B.; Dahame, T.; Benghia, A., First-Principles Investigation on the Stability and Material Properties of All-Inorganic Cesium Lead Iodide Perovskites CsPbI3 Polymorphs. Physica B: Condensed Matter 2020, 585 (41), pp 2118-2124.
59. Wang, H.; Zhang, P.; Zang, Z., High Performance CsPbBr3 Quantum Dots Photodetectors by Using Zinc Oxide Nanorods Arrays as an Electron-Transport Layer. Applied Physics Letters 2020, 116 (16), pp 2103-2107.
60. Li, Y.; Shi, Z.-F.; Li, X.-J.; Shan, C.-X., Photodetectors Based on Inorganic Halide Perovskites: Materials and Devices. Chinese Physics B 2019, 28 (1), pp 7803-7817.
61. Wu, C. Y.; Peng, W.; Fang, T.; Wang, B.; Xie, C.; Wang, L.; Yang, W. H.; Luo, L. B., Asymmetric Contact‐Induced Self‐Driven Perovskite‐Microwire‐Array Photodetectors. Advanced Electronic Materials 2019, 5 (5), 1900135.
62. Song, J.; Xu, L.; Li, J.; Xue, J.; Dong, Y.; Li, X.; Zeng, H., Monolayer and Few-Layer All-Inorganic Perovskites as a New Family of Two-Dimensional Semiconductors for Printable Optoelectronic Devices. Advanced Materials 2016, 28 (24), pp 4861-4869.
63. Zhou, Y.; Luo, J.; Zhao, Y.; Ge, C.; Wang, C.; Gao, L.; Zhang, C.; Hu, M.; Niu, G.; Tang, J., Flexible Linearly Polarized Photodetectors Based on All-Inorganic Perovskite CsPbI3 Nanowires. Advanced Optical Materials 2018, 6 (22), 1800679.
64. Li, C.; Han, C.; Zhang, Y.; Zang, Z.; Wang, M.; Tang, X.; Du, J., Enhanced Photoresponse of Self-Powered Perovskite Photodetector Based on ZnO Nanoparticles Decorated CsPbBr3 Films. Solar Energy Materials and Solar Cells 2017, 172, pp 341-346.
65. Hsiao,Y.-C. Enchanced Performances Photodetetctor Based on CsPbBr3 Nanocrystals by Formimg Heterojunction with CsPbI3 Nanorods and Utilizing Localized Surface Plasmonic Effect of Gold Nanoparticles. MS Thesis, Department of Materials Science and Engineering, National Tsing Hua University, 2020.
66. Tsai, P.-H. Enchanced Performance Photodetetctor Based on Ag Nanoparticles / CsPbBr1.2I1.8 Quantum Dots. MS Thesis, Department of Materials Science and Engineering, National Tsing Hua University, 2019.
67. Dorodnyy, A.; Salamin, Y.; Ma, P.; Plestina, J. V.; Lassaline, N.; Mikulik, D.; Romero-Gomez, P.; i Morral, A. F.; Leuthold, J., Plasmonic Photodetectors. IEEE Journal of Selected Topics in Quantum Electronics 2018, 24 (6), pp 1-13.
68. West, P. R.; Ishii, S.; Naik, G. V.; Emani, N. K.; Shalaev, V. M.; Boltasseva, A., Searching for Better Plasmonic Materials. Laser & Photonics Reviews 2010, 4 (6), pp 795-808.
69. Jokar, E.; Cai, L.; Han, J.; Nacpil, E. J. C.; Jeon, I., Emerging Opportunities in Lead-Free and Lead–Tin Perovskites for Environmentally Viable Photodetector Applications. Chemistry of Materials 2023, 35 (9), pp 3404-3426.
70. Gao, Z.; Zhou, H.; Dong, K.; Wang, C.; Wei, J.; Li, Z.; Li, J.; Liu, Y.; Zhao, J.; Fang, G., Defect Passivation on Lead-Free CsSnI3 Perovskite Nanowires Enables High-Performance Photodetectors with Ultra-High Stability. Nano-Micro Letters 2022, 14 (1), pp 215-224.
71. Qi, Z.; Fu, X.; Yang, T.; Li, D.; Fan, P.; Li, H.; Jiang, F.; Li, L.; Luo, Z.; Zhuang, X., Highly Stable Lead-Free Cs3Bi2I9 Perovskite Nanoplates for Photodetection Applications. Nano Research 2019, 12 (8), pp 1894-1899.
72. Liu, P.; Liu, Y.; Zhang, S.; Li, J.; Wang, C.; Zhao, C.; Nie, P.; Dong, Y.; Zhang, X.; Zhao, S., Lead‐Free Cs3Sb2Br9 Single Crystals for High Performance Narrowband Photodetector. Advanced Optical Materials 2020, 8 (21), 2001072.