本實驗主要探討有機光電容元件的光暫態電流響應，光電容元件的結構為金屬/介電層/半導體/金屬(metal/insulator/semiconductor/metal, MISM)的三明治結構，利用插入介電層使電子能累積在介電層側，產生光暫態電流。此研究中，利用聚偏二氟乙烯(polyvinylidene difluoride, PVDF)和聚(3-己烷基噻吩)(poly(3-hexylthiophene), P3HT)及富勒烯衍生物 ([6,6]-phenyl-C61-butyric acid methyl ester, PCBM)的混和主動層製成MISM結構，由PVDF層的引入，使常見的P3HT:PCBM太陽能電池產生光暫態電流，並在研究中改變不同變因分別討論。而由前半討論可知，介電層為影響光暫態電流的主因，厚度的改變會影響累積電子的數目，因此我們提出了藉由外力改變介電層厚度的方式以提升光暫態電流的假設，並在後半藉由元件量測上的設計，成功的利用外力改變介電層厚度，並驗證假設提升了光暫態電流。由以上，我們確認了光暫態電流變化和介電層的相對關係，並初步驗證了壓電效應理論。

In this study, we successful demonstrated the poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C61-butyric(P3HT:PCBM) based photocapacitance device. In which, the Metal/Insulator/Semiconductor/Metal (MISM) model is applied to detect transient photocurrent where polyvinylidene difluoride(PVDF) is used in different concentration to form insulator layer.
In common, optoelectronic device, the dominant the transient photocurrent phenomenon is dominantal by the properties of insulator layer. In the contract, by varying the insulator layer, active layer, metal electrode and incident light, we can able to produce decent photocapacitance device with better transient photocurrent. Beside that, piezoelectric effect also is observed in our study when apply external pressure on device with thin insulator while transient photocurrent is enhanced.
By this study, new biomedical equipment is established, and there is a good candidate for conversion mechanical energy to electrical energy.

[1] M. Hatano, S. Kambara, and S. Okamoto, “Paramagnetic and electric properties of polyacetylene”, J. Polym. Sci. 51, 26 (1961).
[2] H. Shirakawa, E. J. Louis, A. G. MacDiarmid, C. K. Chiang, and A. J. Heeger, “Synthesis of electrically conducting organic polymers: halogen derivatives of polyacetylene, (CH)x”, J. Chem. Soc. Chem. Commun. 16, 578-580 (1977).
[3] M. Lenes, G.-J. A. H. Wetzelaer, F. B. Kooistra, S. C. Veenstra, J. C. Hummelen, and P. W. M. Blom, “Fullerene bisadducts for enhanced open-circuit voltages and efficiencies in polymer solar cells”, Adv. Mater. 20, 2116 (2008).
[4] D. Mühlbacher, M. Scharber, M. Morana, Z. Zhu, D. Waller, R. Gaudiana, and C. Brabec, “High photovoltaic performance of a low-bandgap polymer”, Adv. Mater. 18, 2884 (2006).
[5] B. Geffroy, P. le Roy, and C. Prat, “Organic light-emitting diode (OLED) technology: materials, devices and display technologies”, Polym. Int. 55, 572 (2006).
[6] S. Reineke, M. Thomschke, B. Lüssem, and K. Leo, “White organic light-emitting diodes: status and perspective”, Rev. Mod. Phys. 85, 1245 (2013).
[7] C. D. Sheraw, L. Zhou, J. R. Huang, D. J. Gundlach, and T. N. Jackson, “Organic thin-film transistor-driven polymer-dispersed liquid crystal displays on flexible polymeric substrates”, Appl. Phys. Lett. 80, 1088 (2002).
[8] D. Elkington, N. Cooling, W. Belcher, P. C. Dastoor, and X. Zhou, “Organic thin-film transistor (OTFT)-based sensors”, Electronics 3, 234 (2014).
[9] S. Tiwari, and N. C. Greenham, “Charge mobility measurement techniques in organic semiconductors”, Opt. Quant. Electron. 41, 69 (2009).
[10] M. Shibata, Y.Sakai, and D. Yokoyama, “Advantages and disadvantages of vacuum-deposited and spin-coated amorphous organic semiconductor films for organic light-emitting diodes”, J. Mater. Chem. C 3, 11178 (2015).
[11] Y. Yamashita, “Organic semiconductors for organic field-effect transistors”, Sci. Technol. Adv. Mater. 10, 024313 (2009).
[12] Y.-J. Cheng, S.-H. Yang, and C.-S. Hsu, “Synthesis of conjugated polymers for organic solar cell applications”, Chem. Rev. 11, 5868 (2009).
[13] C. Cocoyer, L. Rocha, L. Sicot, B. Geffroy, R. de Bettignies, C. Sentein, C. Fiorini-Debuisschert, and P. Raimond, “Implementation of submicrometric periodic surface structures toward improvement of organic-solar-cell performances”, Appl. Phys. Lett. 88, 133108 (2006).
[14] J. V. de Lagemaat, T. M. Barnes, G. Rumbles, S. E. Shaheen, and T. J. Coutts, “Organic solar cells with carbon nanotubes replacing In2O3:Sn as the transparent electrode”, Appl. Phys. Lett. 88, 233503 (2006).
[15] I. Torres, D. M. Taylor, and E. Itoh, “Interface states and depletion-induced threshold voltage instability in organic metal-insulator-semiconductor structures”, Appl. Phys. Lett. 85, 314 (2004).
[16] K. Nakamura, T. Hata, A. Yoshizawa, K. Obata, H. Endo, and K. Kudo, “Improvement of metal-insulator-semiconductor-type organic light-emitting transistors”, Jpn. J. Appl. Phys. 47, 1889 (2008).
[17] K. Nakamura, T. Hata, and A. Yoshizawa, “Metal-insulator-semiconductor-type organic light-emitting transistor on plastic substrate”, Appl. Phys. Lett. 89, 103525 (2006).
[18] R. Har-Lavan, I. Ron, F. Thieblemont, and D. Cahen, “Toward metal-organic insulator-semiconductor solar cells, based on molecular monolayer self-assembly on n-Si”, Appl. Phys. Lett. 94, 043308 (2009).
[19] T. Tanaka, and Y. Inuishi, “Photoconduction of high-density polyethylene”, Jpn. J. Appl. Phys. 6, 1371 (1967).
[20] K.-J. Baeg, M. Binda, D. Natali, M. Caironi, and Y.-Y. Noh, “Organic light detectors: photodiodes and phototransistors”, Adv. Mater. 25, 4267 (2013).
[21] L. Hu, A. Iwasaki, R. Suizu, H. Yoshikawa, K. Awaga, and H. Ito, “Highly efficient alternating photocurrent from interactive organic-radical dimers: a novel light-harvesting mechanism for optoelectronic conversion”, Chem. Phys. Lett. 484, 177 (2010).
[22] L. Hu, Y. Noda, H. Ito, H. Kishida, A. Nakamura, and K. Awaga, “Optoelectronic conversion by polarization current, triggered by space charges at organic-based interfaces”, Appl. Phys. Lett. 96, 243303 (2010).
[23] L. Reissig, S. Dalgleish, and K. Awaga, “A differential photodetector: detecting light modulations using transient photocurrents”, AIP Adv. 6, 015306 (2016).
[24] P. Sundberg, and M. Karppinen, “Organic and inorganic-organic thin film structures by molecular layer deposition: a review”, Beilstein J. Nanotechnol. 5, 1104 (2014).
[25] D. B. Mitzi, K. Chondroudis, and C. R. Kagan, “Organic-inorganic electronics”, J. Res. Dev. 45, 29 (2001).
[26] I. Kang, H.-J. Yun, D. S. Chung, S.-K. Kwon, and Y.-H. Kim, “Record high hole mobility in polymer semiconductors via side-chain engineering”, J. Am. Chem. 40, 14896 (2013).
[27] M. V. Jacob, C. D. Easton, G. S. Woods, and C. C. Berndt, “Fabrication of a novel organic polymer thin film”, Thin Solid Films 516, 3884 (2008).
[28] W. Brütting, ed., “Introduction to the physics of organic semiconductors”, Physics of Organic Semiconductors, 1, Wiley-VCH (2005).
[29] N. Karl, and J. Marktanner, “Electron and hole mobilities in high purity anthracene single crystals”, Mol. Cryst. Liq. Cryst. 355, 149 (2001).
[30] S. M. Sze, “Energy bands and carrier concentration in thermal equilibrium”, Semiconductor devices: Physics and Technology, 2, Wiley New York (2001).
[31] Q. L. Song, H. R. Wu, X. M. Ding, and X. Y. Hou, “Exciton dissociation at the indium tin oxide-N,N’-bis(naphthalen-1-yl)-N,N’-bis(phenyl) benzidine interface: a transient photovoltage study”, Appl. Phys. Lett. 88, 232101 (2006).
[32] Q. L. Song, C. M. Li, M. B. Chan-Park, M. Lu, H. Yang, and X. Y. Hou, “Exciton dissociation in organic light emitting diodes at the donor-acceptor interface”, Phys. Rev. Lett. 98, 176403 (2007).
[33] L. Hu, X. Liu, S. Dalgleish, M. M. Matsushita, H. Yoshikawa, and K. Awaga, “Organic optoelectronic interfaces with anomalous transient photocurrent”, J. Mater. Chem. C 3, 5122 (2015).
[34] R. M. White, and F. W. Voltmer, “Direct piezoelectric coupling to surface elastic waves”, Appl. Phys. Lett. 7, 314 (1965).
[35] J. Curie, and P. Curie, “Développement par compression de l'électricité polaire dans les cristaux hémièdres à faces inclines”, Bulletin de Minéralogie 4, 90 (1880).
[36] J.-P. Adloff, “A short history of polonium and radium”, Chem. Int. 33, 1 (2011).
[37] G. Li, V. Shortriya, J. Huang, T. Moriarty, K. Emery, and Y. Yang, “High-efficiency solution processible polymer photovoltaic cells by self-organization of polymer blends”, Nat. Mater. 4, 864 (2005).
[38] W. Ma, C. Yang, X. Gong, K. Lee, and A. J. Heeger, “Thermally stable, efficiency polymer solar cells with nanoscale control of the interpenetrating network morphology”, Adv. Funct. Mater. 15, 1617 (2005).
[39] L. Hu, S. Dalgleish, M. M. Matsushita, H. Yoshikawa, and K. Awaga, “Storage of an electric field for photocurrent generation in ferroelectric-functionalized organic devices”, Nat. Comm. 5, 3279 (2014).
[40] L. J. A. Koster, V. D. Mihailetchi, and P. W. M. Blom, “Ultimate efficiency of polymer/fullrene bulk heterojunction solar cell”, Appl, Phys. Lett. 88, 093511 (2006).