臺灣博碩士論文加值系統

本論文主要探討銅銦鋁二硒相關薄膜作為光檢測器吸收層之研究。藉由調整銅、銦、鋁元素在銅銦鋁合金先驅物中的比例，並使用適當的硒化和硫化製程，我們獲得銅銦鋁二硒和銅銦鋁二硫薄膜並分別應用於近紅外光及紫外光光檢測器。本研究內容主要分成三個部份﹕首先，探討金屬-半導體-金屬(金半金)結構的近紅外光光檢測器；接下來研究金半金和奈米結構近紅外光光檢測器之差異；最後我們討論銅銦鋁二硫薄膜及其應用於紫外光光檢測器。
在第一部份中，我們探討新穎材料銅銦鋁二硒薄膜應用於金半金結構的近紅外光光檢測器。此種材料有極高的光吸收係數、量子效率和轉換效率，所以可使用於光電元件如光檢測器。藉由調變鋁/銦+鋁的比例，如變化從0至0.5，所對應的薄膜能隙為1.02至1.7 eV，此為在近紅外光的波長範圍內(700-2500 nm)。藉由使用最佳的硒化製程，我們獲得極大的銅銦鋁二硒晶粒(2-5 μm)。金半金電極間距和薄膜的晶粒大小對於光電流放大扮演非常重要的角色。相較於電極間距10 μm的光檢測器，電極間距5 μm的元件因為電極之間有著較少的晶粒邊界，所以呈現出104倍數的光電流放大效果。另外，光響應數據指出光檢測器的截止頻率大約落在790 nm，此結果與我們光激發螢光的分析相呼應。
在第二部份中，我們討論兩種不同結構的銅銦鋁二硒近紅外光光檢測器：金半金簡單平面式和奈米結構環狀p-n接面垂直式。奈米結構光檢測器的組成為: 銅銦鋁二硒/硒化鋅奈米線/硒化鋅/鉬/銦錫氧化物玻璃基板。硒化鋅奈米線是由氧化鋅奈米線經由硒化製程而得，並因為鑲嵌於銅銦鋁二硒薄膜中，所以可改善光檢測器的光電流放大效能。實驗結果指出，奈米結構環狀p-n接面垂直式光檢測器擁有102倍數的光電流放大，然而金半金簡單平面式只有101倍數。原因如下：在垂直式結構中，電極間有較少的晶粒邊界，並且載子收集路徑較短，因此被復合的機率較小。另外，光響應結果顯示此兩種結構的截止頻率均落在790 nm處。
在第三部份中，我們研究銅銦鋁二硫薄膜及其應用於紫外光光檢測器，並使用兩種結構：金半金和簡單p-n接面。銅鋁二硫相關薄膜因為具有大的直接能隙、在紫外光範圍有超過90% 的吸收係數以及-2.1% 至21% 的反射係數，使得它適合應用於紫外光光檢測器。在銅鋁二硫薄膜中，我們使用少量的銦取代鋁，使其形成銅銦鋁二硫薄膜並且其能隙大小位於UV-A的輻射範圍中(320-400 nm)。在形成銅銦鋁二硫薄膜的過程中，我們遭遇很大的挑戰，但是藉由適當的快速熱退火與硫化製程，可獲得沒有存在其他二元項與裂痕的薄膜。在電性探討方面，結果指出在簡單p-n接面的紫外光光檢測器中，光電流放大優於金半金結構的檢測結果。此外，在金半金簡單平面式的量測中，相較於電極間距10 μm的光檢測器，電極間距5 μm的元件具有較佳的光電流放大效果。

In this dissertation, we investigate Cu(In,Al)Se2 related thin films as absorption layer in photodetector. By modifying the concentration of Cu, In, and Al in the precursor of CuInAl alloy and using appropriate selenization or sulfurization process, we obtain Cu(In,Al)Se2 or Cu(In,Al)S2 thin films with suitable bandgap for near-infrared (NIR) or ultraviolet (UV) photodetector, respectively. The thesis contents have three distinct subjects. In the first subject, metal-semiconductor-metal (MSM) NIR photodetector is studied. In the second subject, the distinction of detecting schemes between MSM and nano-structured NIR photodetector is evaluated. Finally, we focus on the characteristics of Cu(In,Al)S2 thin film and its applications for UV photodetector.
In the first subject, a novel application of Cu(In,Al)Se2 thin film for MSM NIR photodetector is demonstrated. Cu(In,Al)Se2 materials have a high optical absorption coefficient, high quantum efficiency and high conversion efficiency, so they are attractive candidates for photodetector. By adjusting the ratio of Al/ In+Al from 0 to 0.5, the corresponding bandgap of the Cu(In,Al)Se2 thin film are 1.02-1.7 eV, which are within the range of NIR wavelength (700-2500 nm). We have achieved a single phased polycrystalline Cu(In,Al)Se2 thin film with smooth surface and super large (2-5 μm) grains by using optimal selenization process. The MSM finger spacing and grain size of the film play an important role on the photocurrent amplification. The photodetector with 5-μm electrode spacing demonstrated a four-order of magnitude in photocurrent amplification due to fewer grain boundaries. The photo response data suggest that the Cu(In,Al)Se2 NIR photodetectors have a cut-off frequency near 790 nm and is in agreement with the results of the photoluminescence (PL) analysis.
In the second subject, we demonstrate nano-structured Cu(In,Al)Se2 NIR photodetectors. The Cu(In,Al)Se2 NIR photodetectors were fabricated on ZnO nanowires/ZnO/Mo/ITO glass substrate. Cu(In,Al)Se2 thin film acted as a sensing layer and sparse ZnSe nanowires, which converted from ZnO nanowires after selenization process, were embedded in the Cu(In,Al)Se2 thin film to improve the amplification performance of the NIR photodetectors. Two detection schemes, a plain Al-Cu(In,Al)Se2-Al MSM structure and a vertical structure with Cu(In,Al)Se2/ZnSe nanowires annular p-n junction, are studied. The nano-structured NIR photodetector demonstrate two orders of magnitude for the annular p-n junction and one order of magnitude for the MSM structure in photocurrent amplification. The nano-structured photodetector with annular p-n junction exhibits a better amplification because of fewer grain boundaries between sensing electrodes, nano-structured detection scheme having a shorter distance for carrier collections, and carrier generated near the p-n junctions. The responsivities of the photodetectors using both sensing structures have the same cut-off frequency near 790 nm.
In the third subject, we study the characteristics of Cu(In,Al)S2 thin film and its application to UV photodetectors using MSM and plain p-n junction sensing structures. CuAlS2-based materials have a wide direct bandgap, rather low melting point, high absorbance of over 90% in the ultraviolet region, and a low reflectance range of -2.1%-21% in near ultraviolet region. Consequently, they have potential to be used in UV photodetectors. By replacing Al with a small amount of In in a CuAlS2 thin film, the bandgap of Cu(In,Al)S2 thin film can be adjusted to be within the UV-A radiation range of 320-400 nm. Formation of Cu(In,Al)S2 thin film suitable for UV detection is a challenging task. We realized the film using rapid thermal annealing and sulfurization process. The I-V characteristics also show that the photocurrent amplification via a plain p-n junction is better than that of a plain MSM structure. In addition, the I-V characteristics with 5-μm electrode spacing are superior to that of the 10-μm finger spacing for the MSM-structured UV photodetector.

Contents
Abstract (in Chinese) I
Abstract (in English) IV
Acknowledgements VII
Contents IX
Table captions XIV
Figure captions XV

Chapter 1 Introduction………………………………………………….... 1
§ 1.1 Background…………………………………………………… 1
(1)Near-infrared Photodetector………………………… 1
(2)Ultraviolet Photodetector…………………………… 1
§ 1.2 Motivation…………………………………………………… 2
(1)Near-infrared Photodetector………………………… 2
(2)Ultraviolet Photodetector…………………………… 3
§ 1.3 Organization of this dissertation…………………4
§ References in chapter 1……………………………………… 6
Chapter 2 Theory and Literature Reviews…………………………… 9
§ 2.1 Metal-semiconductor contact………………………… 9
2.1.1 Interface theory……………………………… 9
2.1.2 Current transport mechanism……………10
§ 2.2 Semiconductor photodetector……………………… 11
2.2.1 Principle of operation……………………11
2.2.2 Metal-semiconductor-metal (MSM) photodetector............................................11
2.2.3 P-n junction photodetector.........13
§ 2.3 Schottky barrier height………………………………14
§ References in chapter 2…………………………………… 25
Chapter 3 Characteristics of Cu(In,Al)Se2 thin film……… 27
§ 3.1 Material properties of CuInSe2 thin film……27
§ 3.2 Growth methods of Cu(In,Al)Se2 thin film...28
3.2.1 Co-evaporation……………………………… 28
3.2.2 Chemical bath deposition (CBD)………29
3.2.3 Selenization……………………………………29
§ 3.3 Cu(In,Al)Se2 thin film as an absorber in near-infrared photodetector...................................30
§ References in chapter 3………………………………………33
Chapter 4 Experimental Scheme…………………………………….....36
§ 4.1 Experimental materials……………………………….36
§ 4.2 Process equipments……………………………………..36
4.2.1 Sputter system……………………………….36
4.2.2 Electrochemical plating system………37
4.2.3 Selenization system……………………….38
4.2.4 Single-side mask aligner……………….39
4.2.5 Thermal evaporation system…………….39
4.2.6 Rapid thermal annealing system(RTA).40
4.2.7 Sulfurization furnace………………………40
§ 4.3 Analytical instruments…………………………………41
4.3.1 Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDXS)……….....41
4.3.2 X-ray Diffraction (XRD)………………..43
4.3.3 Photoluminescence (PL)…………......45
4.3.4 Electrical measurement system……….46
§ References in chapter 4……………………………………60
Chapter 5 Metal-semiconductor-metal near-infrared photodetector with Cu(In,Al)Se2 thin film………………………62
§ 5.1 Motivation………………………………………………..62
§ 5.2 Construction of Cu(In,Al)Se2 photodetector…62
5.2.1 Substrate……………………………….....62
5.2.2 Molybdenum (Mo) layer………………………63
5.2.3 Fabrication of metal-semiconductor-metal (MSM) pattern......................................64
§ 5.3 Experimental procedures…………………………….65
5.3.1 Sample preparation…………………………65
5.3.2 Analytic equipments…………………………66
§ 5.4 Cu(In,Al)Se2 thin film characterization………67
5.4.1 X-ray diffraction patterns of stacked films………………………......................................67
5.4.2 SEM observations of Cu(In,Al)Se2 thin film morphology and cross-sectional view…………………………67
5.4.3 Photoluminescence analysis of Cu(In,Al)Se2 thin film…67
§ 5.5 Electrical measurements…………………………...68
§ 5.6 Results and discussion…………………………………69
§ 5.7 Summary……………………………………………………...70
§ References in chapter 5………………………………………77
Chapter 6 Nano-structured Cu(In,Al)Se2 near-infrared
photodetectors……………………………………………......79
§ 6.1 Motivation………………………………………………….79
§ 6.2 Literature reviews of nano-structured applications.............................................79
§ 6.3 Experimental procedures……………………………..81
6.3.1 Sample preparation…………………………81
6.3.2 Analytic equipments……………………….82
§ 6.4 Cu(In,Al)Se2 thin film characterization…….83
6.4.1 X-ray diffraction patterns of stacked films....................................................83
6.4.2 SEM observations of ZnO nanowires morphology and cross-sectional view………………………………..83
6.4.3 SEM observations of Cu(In,Al)Se2 thin film morphology and cross-sectional view…………………………84
§ 6.5 Electrical measurements………………………………85
§ 6.6 Results and discussion…………………………………85
§ 6.7 Summary……………………………………………………...86
§ References in chapter 6………………………………………94
Chapter 7 Cu(In,Al)S2 thin film characteristics and ultraviolet photodetector…………..........................96
§ 7.1 Motivation………………………………………………....96
§ 7.2 Introduction of UV photodetector……………...96
§ 7.3 Experimental procedures……………………………..97
7.3.1 Sample preparation………………………..97
7.3.2 Electrodes fabrication……………………98
7.3.2.1 MSM structured photodetector......98
7.3.2.2 P-n junction photodetector………..99
7.3.3 Analytic equipments……………………….99
§ 7.4 Challenges of forming Cu(In,Al)S2 thin films...................................................100
7.4.1 Cu(In,Al)S2 grains with lots of binary phases...........................................100
7.4.2 Cracks in Cu(In,Al)S2 thin films..101
7.4.3 Formation of Cu(In,Al)S2 grains...102
§ 7.5 I-V measurement………………………………………..102
§ 7.6 Summary……………………………………………………..104
§ References in chapter 7…………………………………..124
Chapter 8 Conclusions and prospects……………………………...126
§ 8.1 Conclusions……………………………………………...126
8.1.1 Metal-semiconductor-metal near-infrared photodetector with Cu(In,Al)Se2 thin film......126
8.1.2 Nano-structured Cu(In,Al)Se2 near-infrared photodetectors……………………………...............127
8.1.3 Cu(In,Al)S2 thin film characteristics and ultraviolet photodetector……………………..............127
§ 8.2 Prospects…………………………………………….....128
Appendix A: Author’s related publication list...........130
Appendix B: Author’s Vita……………………………………........132

§ References in chapter 1
1. E. Thrush, O. Levi, L. J. Cook, S. J. Smith, J. S. Harris, and Jr., in Proceedings of
the 26th Annual International Conference of the IEEE, Engineering Medicine and Biology Society (EMBS), San Francisco, CA, (2004), pp. 2080–2081.

2. M. Izzetoglu, S. C. Bunce, K. Izzetoglu, B. Onaral, and K. Pourrezaei, “Functional Brain Imaging Using Near-Infrared Technology, IEEE Eng. Med. Biol. Mag., 26, (2007), pp.38-46.

3. J. Esper, P. Panetta, M. Ryschkewitsch, W. Wiscombe, and S. Neeck, “NASA-GSFC Nano-satellite technology for earth science missions, Acta Astronautica, 46, (2000), pp. 287-296.

4. R. Calarco, M. Fiordelisi, S. Lagomarsino, and F. Scarinci, “Near-infrared metal-semiconductor-metal photodetector integrated on silicon, Thin Solid Films, 391, (2001), pp.138-142.

5. M. Casalino, L. Sirleto, M. Iodice, N. Saffioti, M. Gioffrè, I. Rendina, and G. Coppola, “Cu/p-Si Schottky barrier-based near infrared photodetector integrated with a silicon-on-insulator waveguide, Appl. Phys. Lett., 96, (2010), pp.241112.

6. S. Zhu, M. B. Yu, G. Q. Lo, and D. L. Kwong, “Near-infrared waveguide-based nickel silicide Schottky-barrier photodetector for optical communications, Appl. Phys. Lett., 92, (2008), pp. 081103.

7. W. J. Lai, S. S. Li, C. C. Lin, C. C. Kuo, C. W. Chen, K. H. Chen, and L. C. Chen, “Near infrared photodetector based on polymer and indium nitride nanorod organic/inorganic hybrids, Scr. Mater., 63, (2010), pp. 653-656.

8. B. S. Passmore, J. Wu, M. O. Manasreh, V. P. Kunets, P. M. Lytvyn, and G. J. Salamo, “Room Temperature Near-Infrared Photoresponse Based on Interband Transitions in In0.35Ga0.65As Multiple Quantum Dot Photodetector, IEEE Electron Device Lett., 29, (2008), pp.224-227.

9. P. Sandvik, K. Mi, F. Shahedipour, R. McClintock, A. Yasan, P. Kung, and M. Razeghi, “AlxGa1-xN for solar-blind UV detectors, J. Cryst. Growth, 231, (2001), pp.366-370.

10. K.J. Chen, F.Y. Hung, S.J. Chang, and S.J. Young, “Optoelectronic characteristics of UV photodetector based on ZnO nanowire thin films, J. Alloys Compounds, 479, (2009), pp.674-677.

11. M. Razeghi and A. Rogalski, “Semiconductor ultraviolet detectors, J. Appl. Phys., 79, (1996), pp. 7433.

12. H.M. Manasevit, F.M. Erdmann, and W.I. Simpson, “The Use of Metalorganics in the Preparation of Semiconductor Materials, J. Electrochem. Soc., 118, (1971), pp.1864-1868.

13. I. Akasaki and I. Hayashi, “Research on blue emitting devices, Ind. Sci. Technol., 17, (1976), pp.48.

14. H. Neumann, “Optical properties and electronic band structure of CuInSe2, Sol. Cells, 16, (1986), pp.317-333.

15.M. A. Contreras, B. Egaas, K. Ramanathan, J. Hiltner, A. Swartzlander, F. Hasoon, and R. Noufi, “Progress Toward 20% Efficiency in Cu(In,Ga)Se2 Polycrystalline Thin-film Solar Cells, Prog. Photovoltaics, 7, (1999), pp.311-316.

16. S. Yamanaka, M. Konagai, and K. Takahashi, “Characterization of Copper Indium
Diselenide Thin Films by Raman Scattering Spectroscopy for Solar Cell Applications, Jpn. J. Appl. Phys., 28, (1989), pp.L1337-L1340.

17. K. Ramanathan, M. A. Contreras, C. L. Perkins, S. Asher, F. S. Hasoon, J. Keane, D. Young, M. Romero, W. Metzger, R. Noufi, J. Ward, and A. Duda, “Properties of 19.2% efficiency ZnO/CdS/CuInGaSe2 thin-film solar cells, Prog. Photovoltaics, 11, (2003), pp.225-230.
.
18. J. L. García and C. Guillén, “CuIn1-xAlxSe2 thin films obtained by selenization of evaporated metallic precursor layers, Thin Solid Films, 517, (2009), pp.2240-2243.

19. P. D. Paulson, M. W. Haimbodi, S. Marsillac, R. W. Birkmire, and W. N. Shafarman, “CuIn1-xAlxSe2 thin films and solar cells, J.Appl. Phys., 91, (2002), pp.10153-10156.

20.W. N. Shafarman, S. Marsillac, P. D. Paulson, M. W. Haimbodi, and R. W. Birkmire, in Proceedings of the 29th IEEE Photovoltaic Specialist Conference, New Orleans (IEEE, New York, 2002), pp.519.

21. S. Shirakata, I. Aksenov, K. Sato, and S. Isomura, “Photoluminescence Studies in CuAlS2 Crystals, Jpn. J. Appl. Phys., 31, (1992), pp.L1071-L1074.

22. D. N. Okoli, A. J. Ekpunobi, and C. E. Okeke, “Optical Properties of Chemical Bath Deposited CuAlS2 Thin Films, The Pacific J. Sci. Tech., 7, (2006), pp.59-63.

§ References in chapter 2
1. E. H. Rhoderick and R. H. Williams, “Metal-Semiconductor Contacts, Oxford: Clarendon Press, (1998).

2. S. M. Sze, “Semiconductor Device Physics and Technology, Wiley, (1985), pp.160.

3. S. M. Sze, “Semiconductor Device Physics and Technology, Wiley, (1985), pp.278.

4. S. M. Sze, D. J. Coleman, JR., and A. Loya, “CURRENT TRANSPORT IN METAL-SEMICONDUCTOR-METAL (MSM) STRUCTURES, Solid-State Electronics, 14, (1971), pp.1209-1218.

5. E. Budianu, M. Purica, F. Iacomi, C. Baban, P. Prepelita, and E. Manea, “Silicon metal-semiconductor-metal photodetector with zinc oxide transparent conducting electrodes, Thin Solid Films, 516, (2008), pp.1629-1633.

6. E. Monroy, E. Muñoz, F. J. Sánchez, F. Calle, E. Calleja, B. Beaumont, P. Gibart, J.A. Muñoz, and F. Cussó, “High-performance GaN p-n junction photodetectors for solar ultraviolet applications, Semicond. Sci. Technol., 13, (1998), pp. 1042-1046.

7. G. Y. Xu, A. Salvador, W. Kim, Z. Fan, C. Lu, H. Tang, H. Morkoç, G. Smith, M. Estes, B. Goldenberg, W. Yang, and S. Krishnankutty, “High speed, low noise ultraviolet photodetectors based on GaN p-i-n and AlGaN(p)-GaN(i)-GaN(n) structures, Appl. Phys. Lett., 71, (1997), pp. 2154-2156.

8. A. Osinsky, S. Gangopadhyay, R. Gaska, B. Williams, M. A. Khan, D. Kuksenkov, and H. Temkin, “Low noise p-π-n GaN ultraviolet photodetectors, Appl. Phys. Lett., 71, (1997), pp.2334-2336.

9. J. J. Horng, Y. K. Su, S. J. Chang, T. K. Ko, and S. C. Shei, “Nitride-based Schottky barrier sensor module with high electrostatic discharge reliability, IEEE Photon. Technol. Lett., 19, (2007), pp.717-719.

10. C.H. Chen, S. J. Chang, Y. K. Su, G. C. Chi, J. Y. Chi, C. A. Chang, J. K. Sheu, J. F. Chen, “GaN metal-semiconductor-metal ultraviolet photodetectors with transparent indium-tin-oxide Schottky contacts, IEEE Photon. Technol. Lett., 13, (2001), pp.848-850.

11. R. S. Ohl, “Light-Sensitive Electric Device, U.S. Patent 2,402,662. Field May 27, 1941. Granted June 25, 1946.

12. M. Riordan and L. Hoddeson, “The Origins of the pn Junction, IEEE Spectrum, 34, (1997), pp.46.

13. S. M. Sze and K. K. Ng, “Physics of Semiconductor Devices, 3rd ed., John Wiley ＆ Sons, (2007).

14. S.K. Cheung and N.W. Cheung, “Extraction of Schottky diode parameters from forward current-voltage characteristics, Appl. Phys. Lett., 49, (1986), pp.85-87.

15. H. Norde, “A modified forward I-V plot for Schottky diodes with high series resistance, J. Appl. Phys., 50, (1979), pp.5052-5053.

§ References in chapter 3
1.W. Hörig, H. Neumann, H. Sobotta, B. Schumann, and G. Kühn, “THE OPTICAL
PROPERTIES OF CuInSe2 THIN FILMS, Thin Solid Films, 48, (1978), pp. 67-72.

2.L. L. Kazmerski, M. Hallerdt, P. J. Ireland, R. A. Mickelsen, and W. S. Chen, “Optical properties and grain boundary effects in CuInSe2, Journal of Vacuum Science ＆ Technology A, 1, (1983), pp.395-398.

3.M. L. Fearheily, “The phase relations in the Cu, In, Se system and the growth of CuInSe2 single crystals, Solar Cells, 16, (1986), pp.91-100.

4.S. B. Zhang, S. H. Wei, and A. Zunger, “Stabilization of ternary compounds via ordered arrays of defect pairs, Physical Review Lett., 78, (1997), pp.4059-4062.

5.R. Noufi, R. Axton, C. Herrington, and S. K. Deb, “Electronic properties versus composition of thin films of CuInSe2, Appl. Phys. Lett., 45, (1984), pp.668-670.

6.S. Singhal, A. K. Chawla, S. Nagar, H. O. Gupta, and R. Chandra, “Photoluminescence measurements in the phase transition region of Zn1-xCdxS films, J. Nanopart. Res., 12, (2010), pp.1415-1421.

7.P. D. Paulson, M. W. Haimbodi, S. Marsillac, R. W. Birkmire, and W. N. Shafarman, “CuIn1-xAlxSe2 thin films and solar cells, J.Appl. Phys., 91, (2002), pp.10153-10156.

8.S. Marsillac, P.D. Paulson, M.W. Haimbodi, R.W. Birkmire, and W.N. Shafarman, “High-efficiency solar cells based on Cu(In,Al)Se2 thin films, Appl. Phys. Lett., 81, (2002), pp.1350-1352.

9.B. Kavitha and M. Dhanam, “In and Al composition in nano-Cu(InAl)Se2 thin films from XRD and transmittance spectra, Mater. Sci. Eng. B, 140, (2007) pp.59-63.
10.D. Dwyer, I. Repins, H. Efstathiadis, and P. Haldar, “Selenization of co-sputtered CuInAl precursor films, Sol. Energy Mater. Sol. Cells, 94, (2010), pp.598-605.

11.J. H. Yun, R.B.V. Chalapathy, J. C. Lee, J. Song, K. H. Yoon, “Formation of CuIn1-xAlxSe2 thin films by Selenization of Metallic Precursors in Se Vapor, Solid State Phenomena, 124-126, (2007), pp.975-978.

12.H. Neumann, “Optical properties and electronic band structure of CuInSe2, Sol. Cells, 16, (1986), pp.317-333.

13.M. A. Contreras, B. Egaas, K. Ramanathan, J. Hiltner, A. Swartzlander, F. Hasoon, and R. Noufi, “Progress Toward 20% Efficiency in Cu(In,Ga)Se2 Polycrystalline Thin-film Solar Cells, Prog. Photovoltaics, 7, (1999), pp.311-316.

14. S. Yamanaka, M. Konagai, and K. Takahashi, “Characterization of Copper Indium
Diselenide Thin Films by Raman Scattering Spectroscopy for Solar Cell Applications, Jpn. J. Appl. Phys., 28, (1989), pp.L1337-L1340.

15. E. Thrush, O. Levi, L. J. Cook, S. J. Smith, J. S. Harris, and Jr., in Proceedings of the 26th Annual International Conference of the IEEE, Engineering Medicine and Biology Society (EMBS), San Francisco, CA, (2004), pp. 2080–2081.

16. M. Izzetoglu, S. C. Bunce, K. Izzetoglu, B. Onaral, and K. Pourrezaei, “Functional Brain Imaging Using Near-Infrared Technology, IEEE Eng. Med. Biol. Mag., 26, (2007), pp.38-46.

17. W. N. Shafarman, S. Marsillac, P. D. Paulson, M. W. Haimbodi, and R. W. Birkmire, in Proceedings of the 29th IEEE Photovoltaic Specialist Conference, New Orleans (IEEE, New York, 2002), pp.519.

18. J. Kois, S. Bereznev, E. Mellikov, and A. Öpik, “Electrodeposition of CuInSe2 thin films onto Mo-glass substrates, Thin Solid Films, 511–512, (2006), pp.420-424.
19. R. Calarco, M. Fiordelisi, S. Lagomarsino, and F. Scarinci, “Near-infrared metal-semiconductor-metal photodetector integrated on silicon, Thin Solid Films, 391, (2001), pp.138-142.

20.W. J. Lai, S. S. Li, C. C. Lin, C. C. Kuo, C. W. Chen, K. H. Chen, and L. C. Chen, “Near infrared photodetector based on polymer and indium nitride nanorod organic/inorganic hybrids, Scr. Mater., 63, (2010), pp. 653-656.

21.B. S. Passmore, J. Wu, M. O. Manasreh, V. P. Kunets, P. M. Lytvyn, and G. J. Salamo, “Room Temperature Near-Infrared Photoresponse Based on Interband Transitions in In0.35Ga0.65As Multiple Quantum Dot Photodetector, IEEE Electron Device Lett., 29, (2008), pp.224-227.

§ References in chapter 4
1.K. Wetzig and C. M. Schneider, “Metal based thin films for electronics, 2nd ed., Wiley-VCH, Weinheim, (2006).

2. S. A. Campbell, “The Science and Engineering of Microelectronic Fabrication, 2nd ed., Oxford University Press, (2001).

3. A. J. Bard and L. R. Faulkner, “Electrochemical Methods: Fundamentals and Applications, 2nd ed., John Wiley ＆ Sons, New York, (2000).

4. “Single-Side Mask Aligner, in http://140.116.176.21/www/technique/20071112/single%20side%20mask%20aligner.htm.

5. V. V. Rao, T. B. Ghosh, and K. L. Chopra, “Vacuum Science and Technology, 3rd ed., Sunil Sachdev, (2008).

6. ModelMILA-5000 Infrared Lamp Heating System Instruction Manual, in http://www.ulvac.com/download/mila-5000%20e%20disk/mila5000_hard_.pdf,
ULVAC-RIKO Engineering Department, Inc.

7.P. Luo, P. Yu, R. Zuo, J. Jin, Y. Ding, J. Song, Y. Chen, “The preparation of CuInSe2 films by solvothermal route and non-vacuum spin-coating process, Physica B, 405, (2010), pp.3294-3298.

8. H. Buert and H. Jenett, “Surface and thin film analysis: a compendium of principles, instrumentation, applications, Wiley-VCH, Weinheim, (2002).

9. O. C. Wells, “Scanning electron microscopy, McGraw-Hill, New York, (1974).

10. G. C. Schwartz and K. V. Srikrishnan, “Handbook of semiconductor interconnection technology, 2nd ed., CRC/Taylor ＆ Francis, Boca Raton, FL, (2006).
11. M. Birkholz, P. F. Fewster, and C. Genzel, “Thin film analysis by X-ray scattering, Wiley-VCH, Weinheim, (2006).

12. T. H. Gfroerer, “Photoluminescence in Analysis of Surfaces and Interfaces, John Wiley ＆ Sons Ltd, Chichester, (2000).

§ References in chapter 5
1.J. S. Chen, E. Kolawa, C. M. Garland, M.-A. Nicolet, and R. P. Ruiz, “Microstructure of polycrystalline CuInSe2/Cd(Zn)S heterojunction solar cells, Thin Solid Films, 219, (1992), pp.183-192.

2.F. Kessler and D. Rudmann, “Technological aspects of flexible CIGS solar cells and modules, Sol. Energy, 77, (2004), pp.685-695.

3. J. Hedström, H. Ohlsen, M. Bodegard, A. Kylner, L. Stolt, D. Hariskos, M. Ruckh, and H. –W. Schock, “ZnO/CdS/Cu(In,Ga)Se2 thin film solar cells with improved performance, Proceeding of the 23rd IEEE Photovoltaic Specialist Conference, (1993), pp.364-371.

4. S. H. Wei, S. B. Zhang, and A. Zunger, “Effect of Na on the electrical and structural properties of CuInSe2, J. Appl. Phys., 85, (1999), pp.7214-7218.

5. T. B. Massalski, H. Okamoto, P. R. Subramanian, and L. Kacprzak, “Binary Alloy Phase Diagrams, 2nd ed., William W. Scott, Jr., (1992).

6.J. H. Scofied, A. Duda, D. Albin, B. L. Ballard, and P. K. Predecki, “Sputtered molybdenum bilayer back contact for copper indium diselenide-based polycrystalline thin-film solar cells, Thin Solid Films, 260, (1995), pp.26-31.

7.S. Singhal, A. K. Chawla, S. Nagar, H. O. Gupta, and R. Chandra, “Photoluminescence measurements in the phase transition region of Zn1-xCdxS films, J. Nanopart. Res., 12, (2010), pp.1415-1421.

8.D. C. Perng, J. W. Chen, and C. J. Wu, “Formation of CuInAlSe2 film with double graded bandgap using Mo(Al) back contact, Sol. Energy Mater. Sol. Cells, 95, (2011), pp. 257-260.

9. M. Gloeckler, J. R. Sites, and W. K. Metzger, “Grain-boundary recombination in Cu(In,Ga)Se2 solar cells, J. Appl. Phys., 98, (2005), pp.113704.
10. T. Wada, “Microstructural characterization of high-efficiency Cu(In,Ga)Se2 solar cells, Sol. Energy Mater. Sol. Cells, 49, (1997), pp.249-260.

11.M. Ruckh, D. Schmid, M. Kaiser, R. Schäffler, T. Walter, and H.W. Schock, “Influence of substrates on the electrical properties of Cu(In,Ga)Se2 thin films, Sol. Energy Mater. Sol. Cells, 41/42, (1996), pp.335-343.

12.D. Cahen and R. Noufi, “Defect chemical explanation for the effect of air anneal on CdS/CuInSe2 solar cell performance, Appl. Phys. Lett., 54, (1989), pp.558-560.

13. M. A. Contreras, B. Egaas, K. Ramanathan, J. Hiltner, A. Swartzlander, F. Hasoon, and R. Noufi, “Progress Toward 20% Efficiency in Cu(In,Ga)Se2 Polycrystalline Thin-film Solar Cells, Prog. Photovoltaics, 7, (1999), pp.311-316.

§ References in chapter 6
1. B. M. Kayes, H. A. Atwater, and N. S. Lewis, “Comparison of the device physics principles of planar and radial p-n junction nanorod solar cells, J. Appl. Phys., 97, (2005), pp.114302.

2. J. A. Czaban, D. A. Thompson, and R. R. LaPierre, “GaAs Core-Shell Nanowires for Photovoltaic Applications, Nano Lett., 9, (2009), pp.148-154.

3. Z. Fan, H. Razavi, J. W. Do, A. Moriwaki, O. Ergen, Y.-L. Chueh, P. W. Leu, J. C. Ho, T. Takahashi, L. A. Reichertz, S. Neale, K. Yu, M. Wu, J. W. Ager, and A. Javey, “Three-dimensional nanopillar-array photovoltaics on low-cost and flexible substrates, Nat. Mater., 8, (2009), pp.648-653.

4. J. Zhu, Z. Yu, G. F. Burkhard, C. M. Hsu, S. T. Connor, Y. Xu, Q. Wang, M. McGehee, S. Fan, and Y. Cui, “Optical Absorption Enhancement in Amorphous Silicon Nanowire and Nanocone Arrays, Nano Lett., 9, (2009), pp.279-282.

5. Y. -J. Lee, D. S. Ruby, D. W. Peters, B. B. McKenzie, and J. W. P. Hsu, “ZnO Nanostructures as Efficient Antireflection Layers in Solar Cells, Nano Lett., 8, (2008), pp.1501-1505.

6. Z. Wu, Y. Zhang, J. Zheng, X. Lin, X. Chen, B. Huang, H. Wang, K. Huang, S. Li, and J. Kang, “An all-inorganic type-II heterojunction array with nearly full solar spectral response based on ZnO/ZnSe core/shell nanowires, J. Mater. Chem., 21, (2011), pp.6020-6026.

7.K. Yu and J. Chen, “Enhancing Solar Cell Efficiencies through 1-D Nanostructures, Nanoscale Res. Lett., 4, (2009), pp.1-10.

8.S. Singhal, A. K. Chawla, S. Nagar, H. O. Gupta, and R. Chandra, “Photoluminescence measurements in the phase transition region of Zn1-xCdxS films, J. Nanopart. Res., 12, (2010), pp.1415-1421.

9.D. C. Perng, J. F. Fang, and J. W. Chen, “Nano-Structured ZnSe/CIS Heterojunction Solar Cells with ZnSe/ZnO Coaxial Nanowires, J. Electrochem. Soc., 158, (2011), pp.H1097-H1011.

10.R. P. Chang and D. C. Perng, “Near-infrared photodetector with CuIn1-x AlxSe2 thin film, Appl. Phys. Lett., 99, (2011), pp.081103.

11.J. R. Tuttle, D.S. Albin, and R. Noufi, “Thoughts on the microstructure of polycrystalline thin film CuInSe2 and its impact on material and device performance, Sol. Cells, 30, (1991), pp.21-38.

12.C. J. Hibberd, K. Ernits, M. Kaelin, U. Müller, and A. N. Tiwari, “Chemical Incorporation of Copper into Indium Selenide Thin-films for Processing of CuInSe2 Solar Cells, Prog. Photovolt: Res. Appl., 16, (2008), pp.585-593.

13.J. S. Chen, E. Kolawa, C. M. Garland, M.-A. Nicolet, and R. P. Ruiz, “Microstructure of polycrystalline CuInSe2/Cd(Zn)S heterojunction solar cells, Thin Solid Films, 219, (1992), pp.183-192.

14.T. Wada, “Microstructural characterization of high-efficiency Cu(In,Ga)Se2 solar cells, Sol. Energy Mater. Sol. Cells, 49, (1997), pp.249-260.

15.D. Cahen and R. Noufi, “Defect chemical explanation for the effect of air anneal on CdS/CuInSe2 solar cell performance, Appl. Phys. Lett., 54, (1989), pp.558-560.

16.S. Armstrong, P. K. Datta, and R. W. Miles, “Properties of zinc sulfur selenide deposited using a close-spaced sublimation method, Thin Solid Films, 403-404, (2002), pp.126-129.

§ References in chapter 7
1.P. Sandvik, K. Mi, F. Shahedipour, R. McClintock, A. Yasan, P. Kung, and M. Razeghi, “AlxGa1-xN for solar-blind UV detectors, J. Cryst. Growth, 231, (2001), pp.366-370.

2.K.J. Chen, F.Y. Hung, S.J. Chang, and S.J. Young, “Optoelectronic characteristics of UV photodetector based on ZnO nanowire thin films, J. Alloys Compounds, 479, (2009), pp.674-677.

3.M. Razeghi and A. Rogalski, “Semiconductor ultraviolet detectors, J. Appl. Phys., 79, (1996), pp. 7433.

4.H.M. Manasevit, F.M. Erdmann, and W.I. Simpson, “The Use of Metalorganics in the Preparation of Semiconductor Materials, J. Electrochem. Soc., 118, (1971), pp.1864-1868.

5.I. Akasaki and I. Hayashi, “Research on blue emitting devices, Ind. Sci. Technol., 17, (1976), pp.48.

6.S. Shirakata, I. Aksenov, K. Sato, and S. Isomura, “Photoluminescence Studies in CuAlS2 Crystals, Jpn. J. Appl. Phys., 31, (1992), pp.L1071-L1074.

7.D. N. Okoli, A. J. Ekpunobi, and C. E. Okeke, “Optical Properties of Chemical Bath Deposited CuAlS2 Thin Films, The Pacific J. Sci. Tech., 7, (2006), pp.59-63.

8.T. B. Massalski, H. Okamoto, P. R. Subramanian, and L. Kacprzak, “Binary Alloy Phase Diagrams, 2nd ed., William W. Scott, Jr., (1992).

9.J. Lewis, “Material challenge for flexible organic devices, materials today, 9, (2006), pp.38-45.

10.F. Smaili, “Effect of Annealing on the Structural and Optical Properties of CuIn1–xAlxS2 Thin Films, Mater. Sci. Appl.,2, (2011), pp.1212-1218.

11.R. Zhang, B. Wang, D. Wan, and L. Wei, “Effects of the sulfidation temperature on the structure, composition and optical properties of ZnS films prepared by sulfurizing ZnO films, Opt. Mater., 27, (2004), pp. 419-423.