臺灣博碩士論文加值系統

本研究以水熱法生長的氧化鋅奈米柱方法，分別製作以鋰參雜氧化鋅奈米柱為P型同質結構以及氧化鎳為P型異質結構的PN接面的紫外光感測器元件，從材料製程當中控制不同參數，探討可能影響因素並選擇表現較優之參數，製作感測器元件並測量光電特性。
第一部分研製同質結構氧化鋅奈米柱紫外光電二極體。採用水熱法在氧化銦錫（ITO）玻璃為基底再濺鍍一層AZO為N型後，生長摻雜鋰ZnO奈米柱結構，將p型NRs堆疊在n型鋁鋅氧化物薄膜上，形成p-n同質結構接面，降低光電二極體的晶格失配。參雜鋰奈米柱經過快速熱退火處理後，由霍爾量測(Hall)、穿透式電子顯微鏡(TEM)、場發射電子顯微鏡(FE-SEM)、二次離子質譜儀、能量散射光譜儀(EDS)等對參雜鋰的氧化鋅奈米柱材料分析，探討不同濃度參雜情形，結果顯示為具有穩定的p型Li-ZnO納米結構，再使用X光繞射(XRD)、螢光光譜儀(PL)對參雜鋰ZnO分析，探討特性較佳的參雜鋰濃度ZnO奈米柱。研究中量測三種不同尺寸的摻雜0.01M鋰濃度製成的同質結構光電二極體（0.5∗0.5、0.75∗0.75 和1∗1mm2）的光電效能。結果顯示在380nm紫外光照射和5v偏壓下，三種光電二極體的光響應率(A/W)分別為21.34、27.94和34.87。以1∗1 mm2元件有光暗電流比1427、UV光-可見光互斥比45.21表現出最好的光電特性。
第二部分為製作p型NiO與n型ZnO為異質結構之紫外光感測器，首先利用射頻磁控濺鍍系統(RF magnetron sputter)在ITO上製作AZO薄膜與NiO薄膜，設定製程的不同的
ii
瓦數、氧氣流量、壓力、熱退火溫度進行材料性質分析。得到以AZO薄膜為晶種層在系統功率30W、製程壓力0.01torr、Ar:O2=12:1、熱退火550℃的參數下，量測得到高的載子濃度-1.1∗1021(1/cm3)與較低的電阻率3.7∗10-3 (Ωcm)；而NiO薄膜在系統功率50W、氧氣流量Ar/O2=5/5、製程壓力0.0075torr參數下，測量得到最高的載子濃度2.1∗1020(1/cm3)與最低的電阻率1.93∗10-1(Ωcm)，顯示增加系統功率、氧氣流量比例和降低製程壓力可以有效的提升載子濃度並降低電阻率，經由UV/VIS/NIR分光光譜儀分析，FE-SEM對薄膜的表面形貌分析，XRD對薄膜的結晶情況分析，以及光激發螢光頻譜進行元件的光響應波段量測。其所製作p-type NiO異質結構元件經過熱退火都呈現較佳的光電特性。經365nm UV光照射下p-NiO/n-AZO紫外光感測器，發現AZO經過熱退火550℃，NiO在製程擇優參數下，在偏壓-1.2V有較佳的光電流-3.2 x10-5A和光響應值為3.68 A/W。由前面選出最好參數所製作p-NiO/n-ZnO NRs元件中，以熱退火550℃的ZnO NRs所製成的p-NiO/n-ZnO NRs紫外光感測器在偏壓-1.2V有最高的光電流-6.35∗10-5A、光暗電流比為5.00且光響應提升到11.3A/W，元件呈現良好的整流特性。

In this study, ZnO nanorods grown by hydrothermal method were used to fabricate PN junction photodetector devices with lithium doped ZnO nanorods as p-type homogeneous structure and nickel oxide as p-type heterostructure, respectively. Different parameters were controlled from the material process to explore the possible influencing factors and select the better parameters to fabricate photodetector devices and measure the photoelectric characteristics.
The first part is the preparation of homogeneous ZnO NRs UV photodiodes. Li doped ZnO NRs were grown on ITO glass substrate by hydrothermal method. P-type NRs were stacked on n-type AZO thin films to form p-n homojunction and reduce the lattice mismatch of photodiodes. After rapid thermal annealing, Li doped ZnO NRs were analyzed by Hall measurement (Hall), transmission electron microscopy (TEM), field emission electron microscopy (FE-SEM), secondary ion mass spectrometry (SIMS) and energy dispersive spectroscopy (EDS). The results showed that Li doped ZnO NRs had stable p-type doped Li ZnO nanostructures, and then X-ray was used to wrap them X-ray diffraction (XRD) and fluorescence spectrometer (PL) were used to analyze the Li doped ZnO NRs, and to explore the better doped lithium concentration ZnO NRs. In this study, the photoelectric efficiency of three homogeneous photodiodes (0.5x0.5, 0.75x0.75 and 1x1mm2) with different sizes of doped 0.01M lithium concentration were measured. The results show that the responsivity (A/W) of the three photodiodes are 21.34, 27.94 and 34.87 under 380nm UV irradiation and 5V bias, respectively. The results show that the best photoelectric characteristics are obtained when the photo-to-dark current ratio is 1427 and the UV to Visible rejection ratio is 45.21.
The second part is the fabrication of p-type NiO and n-type ZnO heterostructure UV sensors. Firstly, AZO and NiO thin films are fabricated on ITO by RF magnetron sputter system. The material properties are analyzed by setting different power, oxygen flow rate, pressure and thermal annealing temperature. High carrier concentration of -1.1x1021 (1/cm3) and low resistivity of 3.7x10-3 were obtained under the conditions of system power of 30W, process pressure of 0.01torr, Ar:O2 = 12:1 and annealing temperature of 550 ℃ The highest carrier concentration of 2.1x1020 (1/cm3) and the lowest resistivity of 1.93x10-1 (Ω cm) were obtained under the system power of 50W, oxygen flow rate of Ar/O2 = 5/5 and process pressure of 0.0075torr. SEM was used to analyze the surface morphology of the film, XRD was used to analyze the crystallization of the film, and photoluminescence spectrum was used to measure the light response band of the device. The p-type NiO heterostructure devices show better photoelectric properties after thermal annealing. The p-NiO/n-AZO UV PDs was irradiated by 365 nm UV light. It was found that AZO after RTA at 550℃, NiO had better photocurrent of -3.2x10-5 A and responsivity value of 3.68 A/W at bias voltage of -1.2V under the process preferred parameters. Among the p-NiO/n-ZnO NRs devices with the best parameters selected above, the p-NiO/n-ZnO NRs UV PDs with thermal annealed ZnO NRs at 550℃ has the highest photocurrent of -6.35x10-5 A, photo-to-dark current ratio of 5.00 and responsivity value of 11.3 A/W at a bias voltage of -1.2V, showing good rectification characteristics.

摘要......i
Abstract......iii
Acknowledgements......v
Table of Contents......vi
List of Tables......x
List of Figures......xi
Chapter 1 Introduction......1
1.1 Background......1
1.2 Motivation......3
1.3 Literature Review......4
Chapter 2 Theory and Principle......6
2.1 Characteristics of ZnO......6
2.1.1 General Properties of ZnO......6
2.1.2 ZnO Optical Properties......8
2.1.3 The Essential Defects of ZnO......8
2.2 Material Characteristics......12
2.2.1 Li Doped ZnO......12
2.2.2 Aluminum Doped Zinc Oxide (AZO)......13
2.2.3 Characteristics of Nickel Oxide (NiO)......14
2.3 The Principle of Film Sputtering and the Growth Mechanism of NRs......16
2.3.1 Principles of Film Deposition......16
2.3.2 Principle of Film Sputtering......17
2.3.3 The Growth Mechanism of NRs......20
2.4 UV Photodiode......22
2.4.1 Operating Theory of Diode......23
2.4.2 Photo-Dark Current......26
2.4.3 Quantum Efficiency......27
2.4.4 Responsivity......28
2.4.5 Internal Gain......29
Chapter 3 Experimental Methods and Procedures......32
3.1 Experimental Chemicals and Instruments......32
3.2 Experimental Framework......34
3.3 Characteristics Analysis of Material and Devices......40
3.3.1 Growth of Li-doped ZnO NRs......40
3.3.2 Fabrication of AZO and NiO Films and Material Characteristics Analysis......41
3.3.3 Fabrication of PN Heterojunction Formed by AZO and NiO Film and its Characteristics Analysis......42
3.3.4 Fabrication of PN Junction Devices Formed by ZnO NRs and NiO......43
3.4 Material Characteristic Analysis Instruments......43
3.4.1 FE-SEM......43
3.4.2 EDS......43
3.4.3 XRD......45
3.4.4 HALL......46
3.4.5 PL......47
3.4.6 TEM......48
3.4.7 SIMS......49
3.5 Semiconductor Parameter Analyzer (HP4156C)......50
Chapter 4 Experimental Results and Discussion of Homo-Structured PDs......51
4.1 Discussion on Homo-Structure and Properties of Li-doped ZnO NRs......51
4.1.1 SEM......53
4.1.2 XRD......56
4.1.3 PL......58
4.1.5 EDS & Mapping......62
4.1.6 SIMS Prove That Li Was Successfully Doped Into ZnO NRs.......66
4.1.7 HALL......67
4.2 Measurement Analysis for Li-doped ZnO NR Homo-Structure Photodiodes......69
4.2.1 IV Measurement and Analysis......69
4.2.2 Responsivity Measurement Analysis......71
4.2.3 Analysis Summary of Homo-Structure PDs for Li-doped ZnO NRs......73
Chapter 5 Experimental Results and Discussion of Heterostructure PDs......74
5.1 RF-Sputter Related Parameters Analysis......74
5.1.1 FE-SEM Structural Characteristics Analysis......74
5.1.2 EDS Component Analysis......81
5.1.3 Hall Measurement Analysis......85
5.1.4 XRD Structure Analysis......87
5.1.5 Absorption Transmittance Analysis......91
5.1.6 PL Photoluminescence Spectrum Analysis......98
5.2 Measurement and Analysis of Hetero-Structure PN Junction UV Photodetectors......99
5.2.1 I-V Measurement Analysis......99
5.2.2 Responsivity Measurement Analysis......100
5.2.3 Analysis Summary of Hetero-Structure UV PDs for NiO and ZnO......101
Chapter 6 Conclusion and Prospect......111
6.1 Conclusion......111
6.2 Prospect......113
Reference......115
Extended Abstract......122

[1] C. F. Landes, S. Link, M. B. Mohamed, B. Nikoobakht and M. A. El-Sayed, 2002, “Some properties of spherical and rod-shaped semiconductor and metal nanocrystals”, Pure Appl. Chem., vol. 74, pp. 1675.
[2] M. B. Mohamed, C. Burda, M. A. El-Sayed and N. Lett., 2001, “Shape dependent ultrafastrelaxation dynamics of CdSe nanocrystals: Nanorods vs nanodots”, Nano Lett., vol. 1, pp. 589.
[3] G. Z. Cao and Y. Wang, 2011, “Synthesis, Properties, and Applications”, Nanostructures and Nanomaterials, 2nd edition, Imperial College Press.
[4] J. H. Park, S. J. Jang, S. S. Kim and B. T. Lee, 2006, “Direct deposition of low temperature ZnO films on (11-20) sapphire substratesby atomic layer deposition”, Appl. Phys. Lett., vol. 89, pp. 121108.
[5] H. F. Liu, N. Xiang and S. J. Chua, 2006, “Flexible piezoelectric nanogenerator system with ZnO epitaxial nanostructures”, Nanotechnology, vol. 17, pp. 5278.
[6] S. N. Cha, J. E. Jang, Y. Chio and G. A. J. Amaratunga, 2006, “Flexible piezoelectric nanogenerator system with ZnO epitaxial nanostructures”, Appl. Phys. Lett., vol. 89, pp. 263102.
[7] L. Vayssieres, K. Keis, S. E. Lindquist and A. Hagfeldt, 2001, “Application of ZnO Nano-Rod and Nano-Film Bilayer Structure on Flexible Dye-Sensitized Solar Cell”, J. Phys. Chem. B, vol. 105, pp. 3350.
[8] M. Guo, P. Diao and S. Cai, 2005, “Hydrothermal growth of well-aligned ZnO nanorod arrays: Dependenc of morphology and alignment ordering upon preparing conditions”, J Solid State Chem, vol. 178, pp. 1864.
[9] S. Vempati, J. Mitra and P. Dawson, 2012, “One-step synthesis of ZnO nanosheets: a blue-white fluorophore”, Nanoscale Res. Lett., vol. 7, pp. 470.
[10] K. Kishino and S. Ishiza, 2015, “Selective-area growth of GaN nanocolumns on Si(111) substrates for application to nanocolumn emitters with systematic analysis of dislocation filtering effect of nanocolumns”, Nanotechnology, vol. 26, pp. 225602.
[11] Y.-L. Chu, L.-W. Ji, H.-Y. Lu, S.-J. Young, I.-T. Tang, T.-T. Chu, J.-S. Guo and Y.-T. Tsai, 2020, “Fabrication and characterization of UV photodetectorswith Cu-doped ZnO nanorod arrays”. J Electrochem Soc, vol. 167, pp. 027522.
[12] S.-J. Young and K.-W. Yuan, 2019, “Self-powered ZnO nanorod ultraviolet photodetector integrated with dye-sensitised solar cell”. J. Electrochem. Soc., vol. 166, pp. B1034.
[13] D.-K. Hwang, S.-H. Kang, J.-H. Lim, E.-J. Yang, J.-Y. Oh, J.-H. Yang, and S.-J. Park, 2005,”p-ZnO/n-GaN heterostructure ZnO light-emitting diodes”, Appl. Phys. Lett., vol. 86, pp. 222101.
[14] S.-Y. Tsai, M.-H. Hon and Y.-M. Lu, 2011, "Fabrication of transparent p-NiO/n-ZnO heterojunction devices for ultraviolet photodetectors", Solid State Electron, vol. 63, pp. 37.
[15] S.-J. Young and Y.-H. Liu, 2018,” Low-frequency noise properties of MgZnO nanorod ultraviolet photodetectors with and without UV illumination”, Sens. Actuator A Phys., vol. 269, pp. 363.
[16] S.-J. Young, C.-C. Yang and L.-T. Lai, 2017,”Review-growth of Al-, Ga-, and In-doped ZnO nanostructures via a low-temperature process and their application to field emission devices and ultraviolet photosensors”, J. Electrochem. Soc., vol. 164, pp. B3013.
[17] S.-J. Young, Y.-H. Liu and L.-T. Lai, 2017, “Fabrication and characterization of aluminum-doped ZnO nanosheets for field emitter application”, ECS J Solid State Sci Technol, vol. 6, pp. 243.
[18] Y.-H. Liu, S.-J. Young, L.-W. Ji and S.-J. Chang, 2015,” UV enhanced field emission properties of Ga-doped ZnO nanosheets”, IEEE Trans Electron Devices, vol. 62, pp. 2033.
[19] Y. Al-Hadeethi, A. Umar, A. A. Ibrahim, S. H. Al-Heniti, R. Kumar, S. Baskoutas and B. M. Raffah , 2017,” Synthesis, characterization and acetone gas sensing applications of Ag-doped ZnO nanoneedles”, Ceram. Int., vol. 43, pp. 6765.
[20] J.-J. Dong, C.-Y. Zhen, H.-Y. Hao, J. Xing, Z.-J. Fan and Z.-L. Zhang, 2014,” Highly ordered ZnO nanostructure arrays: preparation and light-emitting diode application”, J. Appl. Phys., vol. 53, pp. 055201.
[21] C.-L. Hsu, I.-L. Su and T.-J. Hsueh, 2017, “Tunable schottky contact humidity sensor based on S-doped ZnO nanowires on flexible PET substrate with piezotronic effect”, J. Alloys Compd., vol. 705, pp. 722.
[22] A. P. Rambu, L. Ursu, N. Iftimie, V. Nica, M. Dobromir and F. Iacomi , 2013, “Study on Ni-doped ZnO films as gas sensors”, Appl. Surf. Sci., vol. 280, pp. 598.
[23] S.-J. Young and Y.-H. Liu, 2016, “Ultraviolet photodetectors with 2-D Indium-doped ZnO nanostructures”, IEEE Trans Electron Devices, vol. 63, pp. 3160.
[24] R.-C. Wang, H.-Y. Lin, C.-H. Wang and C.-P. Liu, 2012, “Fabrication of a largearea Al-doped ZnO nanowire array photosensor with enhanced photoresponse by straining”, Adv. Funct. Mater., vol. 22, pp. 3875.
[25] N. H. Alvi, W. Ul Hassan, B. Farooq, O. Nur and M. Willander, 2013, “Influence of different growth environments on the luminescence properties of ZnO nanorods grown by the vapor–liquid–solid (VLS) method”, Mater. Lett., vol. 106, pp. 158.
[26] M. Yan, H. T. Zhang, E. J. Widjaja and R. P. H. Chang, 2003, “Self-assembly of well-aligned gallium-doped ZnO nanorods”, J. Appl. Phys., vol. 94, pp. 5240.
[27] S. H. Jung, E. Oh, K. H. Lee, W. Park and S. H. Jeong, 2007, “A sonochemical method for fabricating aligned ZnO nanorods”, Adv. Mater., vol. 19, pp. 749.
[28] R. Shabannia, 2016,” Synthesis and characterization of Cu-doped ZnO nanorods chemically grown on flexible substrate”, J. Mol. Struct., vol. 1118, pp. 157.
[29] S.-J. Chang, B.-G. Duan, C.-H. Hsiao, S.-J. Young, B.-C. Wang, T.-H. Kao, K.-S. Tsai and S.-L. Wu, 2013, “Low-frequency noise characteristics of In-doped ZnO ultraviolet photodetectors”, IEEE Photon. Technol. Lett., vol. 25, pp. 2043.
[30] R. K. Gupta, K. Ghosh and P. K. Kahol, 2009, "Fabrication and characterization of NiO/ZnO p–n junctions by pulsed laser deposition", Physica E Low Dimens. Syst. Nanostruct., vol. 41, pp.617.
[31] M. R. Hasan, T. Xie, S. C. Barron, G. Liu, N. V. Nguyen, A. Motayed, M. V. Rao and R. Debnath, 2015, "Self-powered p-NiO/n-ZnO heterojunction ultraviolet photodetectors fabricated on plastic substrates", APL Mater., vol. 3, pp. 106101.
[32] R. Amiruddin and M. C. Santhosh Kumar, 2016, “Role of p-NiO electron blocking layers in fabrication of (P-N):ZnO/Al:ZnO UV photodiodes", Curr Appl Phys, Vol. 16, pp. 1052.
[33] U. Ozgur, Y. I. Alivov, C. Liu, A. Teke, M. A. Reshchikov, S. Dogan, V. Avrutin, S. J. Cho and H. Morkoc, 2005,”A comprehensive review of ZnO materials and devices”, J. Appl. Phys., vol. 98, pp. 041301.
[34] S. Siva Kumar, P. Venkateswarlu, V. R. Rao, G. N. Rao Kumar et al., 2013, " Synthesis, characterization and optical properties of zinc oxide nanoparticles", International Nano Lett., vol. 3, pp. 30.
[35] A. Pivrikas, N. S. Sariciftci, G. Juska, R. Osterbacka and Prog. Photovolt, 2007, “A review of charge transport and recombination in polymer/fullerene organic solar cells”, Prog Photovolt, vol. 15, pp. 677.
[36] H. Sirringhaus, P. J. Brown, R. H. Friend, M. M. Nielsen, K. Bechgaard, B. M. W. Langeveld-Voss, A. J. H. Spiering, R. A. J. Janssen, E. W. Meijer, P. Herwig and D. M. Leeuw, 1999, “Two-dimensional charge transport in self-organized, high-mobility conjugated polymers”, Nature, vol. 401, pp. 685.
[37] L. Schmidt-Mende and J. L. MacManus-Driscoll, 2007, "ZnO nanostructures, defects, and devices", Mater. Today, vol.10, pp. 40.
[38] S.O. Kasap, 2013, “Optoelectronics and Photonics : Principles and Practices”, Pearson Education, pp. 552.
[39] A. Janotti, C.G. Van de Walle, 2007, “Native point defects in ZnO”, Phys. Rev. B, vol. 76, pp. 165202
[40] D. C. Look, J. W. Hemsky and J. R. Sizelove, 1999, “Residual Native Shallow Donor in ZnO ”, Phys. Rev. Lett., vol. 82, pp. 2552.
[41] R. A. Rakkesh and S. Balakumar, 2014, “Structural, electrical transport and optical studies of Lithium ion doped ZnO nanostructures”, Process. Appl. Ceram., vol. 8, pp. 7.
[42] J. B. Kim, D. Byun, S. Y. Ie, D. H. Park, W. K. Choi, J. W. Choi and B. Angadi, 2008, “Cu-doped ZnO-based p–n hetero-junction light emitting diode”, Semicond Sci Technol, vol. 23, pp. 095004
[43] C. H. Park, S. B. Zhang and S. H. Wei, 2002, “Origin of p-type doping difficulty in ZnO: the impurity perspective”, Phys. Rev. B, vol. 66, pp. 073202.
[44] T. S. Bjorheim, S. Erdal, K. M. Johansen, K. E. Knutsen and T. Norby, 2012 ,”H and Lithium related defects in ZnO and their effect on electrical properties”, J. Phys. Chem. C, vol. 116, pp. 23764.
[45] K. C. Pradel, W. Z. Wu, Y. S. Zhou, X. N. Wen, Y. Ding and Z. L. Wang , 2013,” Piezotronic effect in solution-grown p-Type ZnO nanowires and films”, Nano Lett., vol. 13, pp. 2647.
[46] S. Shin, Y. Kim, M. H. Lee, J. Jung, J. H. Seol and J. Nah, 2014,” Lithium doped zinc oxide nanowires-polymer composite for high performance flexible piezoelectric nanogenerator”, ACS Nano, vol. 8, pp. 10844.
[47] J. Lee, S. Cha, J. Kim, H. Nam, S. Lee, W. Ko, K. L. Wang, J. Park and J. Hong, 2011,” p-Type conduction characteristics of Li-doped ZnO nanowires”, Adv. Mater., vol. 23, pp. 4183.
[48] H. J. Ko, Y. F. Chen, S. K. Hong, H. Wenisch, T. Yao and D. C. Look, 2000,” Gadoped ZnO films grown on GaN templates by plasma-assisted molecular-beam epitaxy”, Appl. Phys. Lett., vol. 77, pp. 3761.
[49] S.-J. Young, C.-C. Yang and L.-T. Lai, 2017, “Review-growth of Al-, Ga-, and In-doped ZnO nanostructures via a low-temperature process and their application to field emission devices and ultraviolet photosensors”, J. Electrochem. Soc., vol. 164, pp. B3013.
[50] S.-J. Young, Y.-H. Liu and L.-T. Lai, 2017,”Fabrication and characterization of aluminum-doped ZnO nanosheets for field emitter application”, ECS J Solid State Sci Technol, vol. 6, pp. 243.
[51] Y.-H. Liu, S.-J. Chang and S.-J. Young, 2016, “Enhanced field emitter base on Indium-doped ZnO nanostructures by aqueous solution”, ECS J Solid State Sci Technol, vol. 5, pp. R203.
[52] H. Shen, H. Zhang, L. Lu, F. Jiang and Y. Chao, 2010, "Preparation and properties of AZO thin films on different substrates", Prog. Nat. Sci., vol. 20, pp. 44.
[53] Ü. Özgür, Y. I. Alivov, C. Liu et al., 2005, "A comprehensive review of ZnO materials and devices", J. Appl. Phys., vol. 98, pp. 041301.
[54] B. D. Cullity and S. R. Stock, 2001," Elements of X-ray Diffraction", Pearson, pp. 48.
[55] Y. J. Zeng, Z. Z. Ye, J. G. Lu, W. Z. Xu, L. P. Zhu, B. H. Zhao and S. Limpijumnong, 2006, “Identification of acceptor states in Li doped p type ZnO thin films”, Appl. Phys. Lett., vol. 89, pp. 042106.
[56] F. Shinoki and A. Itoh, 1975, “Mechanism of rf reactive sputtering”, J. Appl. Phys., vol. 45, pp. 3381.
[57] W. I. Park, C. H. Lee, J. H. Chae, D. H. Lee, and G. C. Yi, 2009, “Ultrafine ZnO nanowire electronic device arrays fabricated by selective metal-organic chemical vapor deposition”, Small, vol. 5, pp. 181.
[58] D. K. Schroder, 2006, “Semiconductor material and device characterization”, John Wiley & Sons, Inc.
[59] E. M. Kaidashev, M. Lorenz, H. von Wenckstern, A. Rahm, H. C. Semmelhack, K. H. Han, G. Benndorf, C. Bundesmann, H. Hochmuth, and M. Grundmann, 2003, “High electron mobility of epitaxial ZnO thin films on c-plane sapphire grown by multistep pulsed-laser deposition”, Appl. Phys. Lett., vol. 82, pp. 3901.
[60]D. Y. Guo, C. X. Shan, S. N. Qu, and D. Z. Shen. , 2014, “Highly sensitive ultraviolet photodetectors fabricated from ZnO quantum dots/carbon nanodots hybrid films", Sci. Rep., vol. 4, pp. 7469.
[61] J. C. Carrano, T. Li, P. A. Grudowski, C. J. Eiting, R. D. Dupuis, and J. C. Campbel, 1997, “High Quantum Efficiency Metal-Semiconductor-Metal Ultraviolet Photodetctors Fabricated on Single-Crystal GaN Epilayers”, Electron. Lett., vol. 33, pp.1980.
[62] J. C. Carrano, T. Li, P. A. Grudowski, C. J. Eiting, R. D. Dupuis, and J. C. Campbell, 1998, “Comprehensive Characterization of Metal-Semiconductor-Metal Ultraviolet Photodetctors Fabricated on Single-Crystal GaN”, J. Appl. Phys., vol. 83, pp. 6148.
[63] K. Ogata, K. Sakurai, Sz. Fujita, Sg. Fujita, K. Matsushige, 2000, ”Effects of thermal annealing of ZnO layers grown by MBE”, J. Cryst. Growth, vol. 214–215, pp. 312.
[64] F. Hossein-babaei and F. Taghibakhsh, 2000, “Electrophoretically deposited zinc oxide thick film gas sensor”, IEEE Xplore, Electron. Lett., vol. 36, pp. 1815.
[65] O. Katz, V. Garber, B. Meyler, G. Bahir and J. Salzman, 2001, “Gain Mechanism in GaN Schottky UV Detectors”, Appl. Phys. Lett., vol. 79, pp. 1417.
[66] C. W. Jia, E. Q. Xie, J. G. Zhao, Z. W. Sun and A. H. Peng, 2006, "Visible and near-infrared photoluminescences of europium-doped titania film", J. Appl. Phys., vol. 100, pp. 023529.
[67] S. Fujihara, C. Sasaki and T. Kimura, 2001, “Effects of Li and Mg doping on microstructure and properties of sol–gel ZnO thin films”, J. Eur. Ceram. Soc., vol. 21, pp. 2109.
[68] K. C. Chiu, Y. W. Kao and J. H. Jean , 2010, “Fabrication of p-type Li-doped ZnO films by RF magnetron sputtering”, J. Am. Ceram. Soc., vol. 93, pp. 1860.
[69] S. Baruah and J. Dutta, 2009, “Hydrothermal growth of ZnO nanostructures”, Science and Technology of Adv. Mater., vol. 10, pp. 013001.
[70] L. N. Demianets, D. V. Kostomarov, 2001, “Mechanism of zinc oxide single crystal growth under hydrothermal conditions”, Ann Chim Sci Mat., vol. 26, pp.193.
[71] X. B. Wang, C. Song, D. M. Li, K. W. Geng, F. Zeng and F. Pan, 2006, “The influence of different doping elements on microstructure, piezoelectric coefficient and resistivity of sputtered ZnO film”, Appl. Surf. Sci., vol. 253, pp. 1639.
[72] R. Tamrakar, M. Ramrakhiani and B. P. Chandra, 2008, “Effect of Capping Agent Concentration on Photophysical Properties of Zinc Sulfide Nanocrystals”, The Open Nanoscience Journal, vol. 2, pp. 12.
[73] A. Saaedi, R. Yousefi, F. Jamali-Sheini, M. Cheraghizade, A. K. Zak and N. M. Huang, 2013, “Optical and electrical properties of p-type Lidoped ZnO nanowires”, Superlattices Microstruct., vol. 61, pp. 91.
[74] R. Yousefi, A. K. Zak and F. Jamali-Sheini, 2013, “The effect of group-I elements on the structural and optical propertiesof ZnO nanoparticles”, Ceram. Int., vol. 39, pp. 1371.
[75] C. Lizandara-Pueyo, S. Dilger, M. R. Wagner, M. Gerigk, A. Hoffmann and S. Polarz, 2014, “Li-doped ZnO nanorods with single-crystal quality—non-classical crystallization and self-assembly into mesoporous materials”, CrystEngComm, vol. 16, pp. 1525.
[76] Y. J. Zeng, Z. Z. Ye, W. Z. Xu, D. Y. Li, J. G. Lu, L. P. Zhu and B. H. Zhao , 2006, “Dopant source choice for formation of p-type ZnO: Li acceptor”, Appl. Phys. Lett., vol. 88, pp. 062107.
[77] J. G. Lu, Y. Z. Zhang, Z. Z. Ye, Y. J. Zeng, H. P. He, L. P. Zhu, J. Y. Huang, L. Wang, J. Yuan, B. H. Zhao and X. H. Li , 2006, “Control of p- and n-type conductivities in Li-doped ZnO thin films”, Appl. Phys. Lett., vol. 89, pp. 112113.
[78] M. Razeghi and A. Rogalski, 1996, “Semiconductor ultraviolet detectors”, J. Appl. Phys., vol. 79, pp. 7433.
[79] S.-M. Peng, Y.-K. Su, L.-W. Ji, S.-J. Young, C.-N. Tsai, J.-H. Hong, Z.-S. Chen and C.-Z. Wu, 2011, “Transparent ZnO nanowire-network ultraviolet photosensor”, IEEE Trans Electron Devices, vol. 58, pp. 2036.
[80] Z.-H. Wang, H.-C. Yu, C.-C. Yang, H.-T. Yeh and Y.-K. Su, 2017, “Low-frequency noise performance of Al-doped ZnO nanorod photosensors by a low-temperature hydrothermal method”, IEEE Trans Electron Devices, vol. 64, pp. 3206.
[81] L.-W. Ji, Y.-J. Hsiao, S.-J. Young, W.-S. Shih, W. Water and S.-M. Lin, 2015, “High-efficient ultraviolet photodetectors based on TiO2/Ag/TiO2 multilayer films”, IEEE Sens. J., vol. 15, pp. 762.