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Role of dopants as a carrier suppressor and strong oxygen binder in amorphous indium-oxide-based field effect transistor

Published online by Cambridge University Press:  27 August 2014

Shanmugam Parthiban  and
Jang-Yeon Kwon
Shanmugam Parthiban
Affiliation:
School of Integrated Technology, and Yonsei Institute of Convergence Technology, Yonsei University, Yeonsu-gu, Incheon 406-840, Korea
Jang-Yeon Kwon*
Affiliation:
School of Integrated Technology, and Yonsei Institute of Convergence Technology, Yonsei University, Yeonsu-gu, Incheon 406-840, Korea
*
a)Address all correspondence to this author. e-mail: jangyeon@yonsei.ac.kr
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Abstract

In this review, we discuss the recent developments of high-performance and improved-stability of indium-oxide-based transparent amorphous-oxide semiconductor (TAOS) thin-film transistors (TFTs) properties. TAOSs are widely explored with the aim of producing high-performance semiconductors suitable for the channel layer of TFTs which enable to survive under light and thermal-bias-induced stress conditions. Numerous TAOSs have been invented with some improved performance characteristics of TFTs such as mobility, light and thermal induced bias stress. However, there has been no clear elucidation of the mechanisms driving these improvements. In this review, we discuss the progression of innovations of high performance indium-oxide-based TAOS TFTs from its first reported amorphous indium gallium zinc oxide (a-IGZO) to present, and their properties that are correlated with the Lewis acid strength (L) and bonding strength of dopant and oxygen as a carrier suppressor and strong binder. The proposed mechanism can be practical to develop novel TAOS TFTs with high mobility and stability.

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Reviews
Information
Journal of Materials Research , Volume 29 , Issue 15 , 14 August 2014 , pp. 1585 - 1596
Copyright
Copyright © Materials Research Society 2014 

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References

REFERENCES

Nomura, K., Ohta, H., Takagi, A., Kamiya, T., Hirano, M., and Hosono, H.: Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors. Nature 432(7016), 488 (2004).CrossRefGoogle ScholarPubMed
Kamiya, T. and Hosono, H.: Material characteristics and applications of transparent amorphous oxide semiconductors. NPG Asia Mater. 2(1), 15 (2010).CrossRefGoogle Scholar
Hosono, H.: Ionic amorphous oxide semiconductors: Material design, carrier transport, and device application. J. Non-Cryst. Solids 352(9), 851 (2006).CrossRefGoogle Scholar
Nomura, K., Takagi, A., Kamiya, T., Ohta, H., Hirano, M., and Hosono, H.: Amorphous oxide semiconductors for high-performance flexible thin-film transistors. Jpn. J. Appl. Phys. 45, 4303 (2006).CrossRefGoogle Scholar
Kamiya, T., Nomura, K., and Hosono, H.: Origins of high mobility and low operation voltage of amorphous oxide TFTs: Electronic structure, electron transport, defects and doping. J. Disp. Technol. 5(12), 468 (2009).CrossRefGoogle Scholar
Kamiya, T., Nomura, K., and Hosono, H.: Present status of amorphous In–Ga–Zn–O thin-film transistors. Sci. Technol. Adv. Mater. 11(4), 044305 (2010).Google Scholar
Jeong, J.K.: The status and perspectives of metal oxide thin-film transistors for active matrix flexible displays. Semicond. Sci. Technol. 26(3), 034008 (2011).Google Scholar
Wager, J.F.: Transparent electronics. Science 300(5623), 1245 (2003).CrossRefGoogle ScholarPubMed
Carcia, P., McLean, R., Reilly, M., and Nunes, G.: Transparent ZnO thin-film transistor fabricated by rf magnetron sputtering. Appl. Phys. Lett. 82(7), 1117 (2003).CrossRefGoogle Scholar
Yabuta, H., Kaji, N., Hayashi, R., Kumomi, H., Nomura, K., Kamiya, T., Hirano, M., and Hosono, H.: Sputtering formation of p-type SnO thin-film transistors on glass toward oxide complimentary circuits. Appl. Phys. Lett. 97(7), 072111 (2010).CrossRefGoogle Scholar
Chiang, H., Wager, J., Hoffman, R., Jeong, J., and Keszler, D.A.: High mobility transparent thin-film transistors with amorphous zinc tin oxide channel layer. Appl. Phys. Lett. 86(1), 013503 (2005).CrossRefGoogle Scholar
Lim, W., Jang, J.H., Kim, S-H., Norton, D., Craciun, V., Pearton, S., Ren, F., and Shen, H.: High performance indium gallium zinc oxide thin film transistors fabricated on polyethylene terephthalate substrates. Appl. Phys. Lett. 93(8), 082102 (2008).Google Scholar
Dehuff, N., Kettenring, E., Hong, D., Chiang, H., Wager, J., Hoffman, R., Park, C-H., and Keszler, D.: Transparent thin-film transistors with zinc indium oxide channel layer. J. Appl. Phys. 97(6), 064505 (2005).CrossRefGoogle Scholar
Kumomi, H., Yaginuma, S., Omura, H., Goyal, A., Sato, A., Watanabe, M., Shimada, M., Kaji, N., Takahashi, K., and Ofuji, M.: Materials, devices, and circuits of transparent amorphous-oxide semiconductor. J. Disp. Technol. 5(12), 531 (2009).CrossRefGoogle Scholar
Jeong, S. and Moon, J.: Low-temperature, solution-processed metal oxide thin film transistors. J. Mater. Chem. C 22(4), 1243 (2012).CrossRefGoogle Scholar
Zilberberg, K., Meyer, J., and Riedl, T.: Solution processed metal-oxides for organic electronic devices. J. Mater. Chem. C 1(32), 4796 (2013).CrossRefGoogle Scholar
Meena, J.S., Chu, M-C., Chang, Y-C., You, H-C., Singh, R., Liu, P-T., Shieh, H-P.D., Chang, F-C., and Ko, F-H.: Effect of oxygen plasma on the surface states of ZnO films used to produce thin-film transistors on soft plastic sheets. J. Mater. Chem. C 1(40), 6613 (2013).CrossRefGoogle Scholar
Yang, W., Song, K., Jeong, Y., Jeong, S., and Moon, J.: Solution-deposited Zr-doped AlOx gate dielectrics enabling high-performance flexible transparent thin film transistors. J. Mater. Chem. C 1(27), 4275 (2013).CrossRefGoogle Scholar
Kang, T.S., Kim, T.Y., Lee, G.M., Sohn, H.C., and Hong, J.P.: Highly stable solution-processed ZnO thin film transistors prepared via a simple Al evaporation process. J. Mater. Chem. C 2(8), 1390 (2014).Google Scholar
Park, S.Y., Kim, K., Lim, K-H., Kim, B.J., Lee, E., Cho, J.H., and Kim, Y.S.: The structural, optical and electrical characterization of high-performance, low-temperature and solution-processed alkali metal-doped ZnO TFTs. J. Mater. Chem. C 1(7), 1383 (2013).CrossRefGoogle Scholar
Banger, K., Yamashita, Y., Mori, K., Peterson, R., Leedham, T., Rickard, J., and Sirringhaus, H.: Low-temperature, high-performance solution-processed metal oxide thin-film transistors formed by a ‘sol–gel on chip’ process. Nat. Mater. 10(1), 45 (2010).Google Scholar
Fortunato, E., Barquinha, P., and Martins, R.: Oxide semiconductor thin-film transistors: A review of recent advances. Adv. Mater. 24(22), 2945 (2012).CrossRefGoogle ScholarPubMed
Presley, R., Munsee, C., Park, C., Hong, D., Wager, J., and Keszler, D.: Tin oxide transparent thin-film transistors. J. Phys. D: Appl. Phys. 37(20), 2810 (2004).Google Scholar
Noh, J.H., Ryu, S.Y., Jo, S.J., Kim, C.S., Sohn, S-W., Rack, P.D., Kim, D-J., and Baik, H.K.: Indium oxide thin-film transistors fabricated by RF sputtering at room temperature. IEEE Electron Device Lett. 31(6), 567 (2010).Google Scholar
Choi, H-S., Jeon, S., Kim, H., Shin, J., Kim, C., and Chung, U-I.: The impact of active layer thickness on low-frequency noise characteristics in InZnO thin-film transistors with high mobility. Appl. Phys. Lett. 100(17), 173501 (2012).CrossRefGoogle Scholar
Feng, Z.C.: Handbook of Zinc Oxide and Related Materials: Devices and Nano-Engineering (CRC Press, Boca Raton, FL, 2012).Google Scholar
Jeong, J.K.: Photo-bias instability of metal oxide thin film transistors for advanced active matrix displays. J. Mater. Res. 28(16), 2071 (2013).Google Scholar
Facchetti, A. and Marks, T.J.: Transparent Electronics (Wiley Online Library, New York, NY, 2010).Google Scholar
King, P. and Veal, T.D.: Conductivity in transparent oxide semiconductors. J. Phys.: Condens. Matter 23(33), 334214 (2011).Google Scholar
Castañeda, L.: Present status of the development and application of transparent conductors oxide thin solid films. Mater. Sci. Appl. 2(9), 1233 (2011).Google Scholar
Calnan, S. and Tiwari, A.: High mobility transparent conducting oxides for thin film solar cells. Thin Solid Films 518(7), 1839 (2010).CrossRefGoogle Scholar
Minami, T.: Transparent conducting oxide semiconductors for transparent electrodes. Semicond. Sci. Technol. 20(4), S35 (2005).Google Scholar
Grundmann, M., Frenzel, H., Lajn, A., Lorenz, M., Schein, F., and von Wenckstern, H.: Transparent semiconducting oxides: Materials and devices. Phys. Status Solidi A 207(6), 1437 (2010).Google Scholar
Parthiban, S., Ramamurthi, K., Elangovan, E., Martins, R., and Fortunato, E.: Spray deposited molybdenum doped indium oxide thin films with high near infrared transparency and carrier mobility. Appl. Phys. Lett. 94(21), 212101 (2009).Google Scholar
Chong, E., Jo, K.C., and Lee, S.Y.: High stability of amorphous hafnium-indium-zinc-oxide thin film transistor. Appl. Phys. Lett. 96(15), 152102 (2010).Google Scholar
Kim, C-J., Kim, S., Lee, J-H., Park, J-S., Kim, S., Park, J., Lee, E., Lee, J., Park, Y., and Kim, J.H.: Amorphous hafnium-indium-zinc oxide semiconductor thin film transistors. Appl. Phys. Lett. 95(25), 252103 (2009).Google Scholar
Fortunato, E., Pereira, L., Barquinha, P., Botelho do Rego, A.M., Gonçalves, G., Vilà, A., Morante, J.R., and Martins, R.F.: High mobility indium free amorphous oxide thin film transistors. Appl. Phys. Lett. 92(22), 222103 (2008).Google Scholar
Cho, D-H., Yang, S., Byun, C., Ryu, M.K., Park, S-H.K., Hwang, C-S., Yoon, S.M., and Chu, H-Y.: Transparent oxide thin-film transistors composed of Al and Sn-doped zinc indium oxide. IEEE Electron Device Lett. 30(1), 48 (2009).CrossRefGoogle Scholar
Yang, S., Cho, D-H., Ryu, M.K., Park, S-H.K., Hwang, C.-S., Jang, J., and Jeong, J.K.: Improvement in the photon-induced bias stability of Al–Sn–Zn–In–O thin film transistors by adopting AlOx passivation layer. Appl. Phys. Lett. 96(21), 213511 (2010).Google Scholar
Cho, D-H., Yang, S., Byun, C., Shin, J., Ryu, M.K., Park, S-H.K., Hwang, C-S., Chung, S.M., Cheong, W-S., and Yoon, S.M.: Transparent Al–Zn–Sn–O thin film transistors prepared at low temperature. Appl. Phys. Lett. 93(14), 142111 (2008).CrossRefGoogle Scholar
Yang, B.S., Huh, M.S., Oh, S., Lee, U.S., Kim, Y.J., Oh, M.S., Jeong, J.K., Hwang, C.S., and Kim, H.J.: Role of ZrO2 incorporation in the suppression of negative bias illumination-induced instability in Zn–Sn–O thin film transistors. Appl. Phys. Lett. 98(12), 122110 (2011).CrossRefGoogle Scholar
Park, J-S., Kim, T-W., Stryakhilev, D., Lee, J-S., An, S-G., Pyo, Y-S., Lee, D-B., Mo, Y.G., Jin, D-U., and Chung, H.K.: Flexible full color organic light-emitting diode display on polyimide plastic substrate driven by amorphous indium gallium zinc oxide thin-film transistors. Appl. Phys. Lett. 95(1), 013503 (2009).CrossRefGoogle Scholar
Allee, D.R., Clark, L.T., Vogt, B.D., Shringarpure, R., Venugopal, S.M., Uppili, S.G., Kaftanoglu, K., Shivalingaiah, H., Li, Z.P., and Ravindra Fernando, J.: Circuit-level impact of a-Si: H thin-film-transistor degradation effects. IEEE Trans. Electron Devices 56(6), 1166 (2009).Google Scholar
Hsu, H-H., Chang, C-Y., and Cheng, C-H.: A flexible IGZO thin-film transistor with stacked TiO2-based dielectrics fabricated at room temperature. IEEE Electron Device Lett. 34(6), 768 (2013).CrossRefGoogle Scholar
Lee, K-H., Jung, J.S., Son, K.S., Park, J.S., Kim, T.S., Choi, R., Jeong, J.K., Kwon, J-Y., Koo, B., and Lee, S.: The effect of moisture on the photon-enhanced negative bias thermal instability in Ga–In–Zn–O thin film transistors. Appl. Phys. Lett. 95(23), 232106 (2009).CrossRefGoogle Scholar
Kwon, J-Y., Lee, D-J., and Kim, K-B.: Review paper: Transparent amorphous oxide semiconductor thin film transistor. Electron. Mater. Lett. 7(1), 1 (2011).CrossRefGoogle Scholar
Ji, K.H., Kim, J-I., Mo, Y-G., Jeong, J.H., Yang, S., Hwang, C-S., Park, S-H.K., Ryu, M-K., Lee, S-Y., and Jeong, J.K.: Comparative study on light-induced bias stress instability of IGZO transistors with SiNx and SiO2 gate dielectrics. IEEE Electron Device Lett. 31(12), 1404 (2010).CrossRefGoogle Scholar
Oh, H., Yoon, S-M., Ryu, M.K., Hwang, C-S., Yang, S., and Park, S-H.K.: Photon-accelerated negative bias instability involving subgap states creation in amorphous In–Ga–Zn–O thin film transistor. Appl. Phys. Lett. 97(18), 183502 (2010).Google Scholar
Chowdhury, M.D.H., Migliorato, P., and Jang, J.: Light induced instabilities in amorphous indium–gallium–zinc–oxide thin-film transistors. Appl. Phys. Lett. 97(17), 173506 (2010).CrossRefGoogle Scholar
Ji, K.H., Kim, J-I., Jung, H.Y., Park, S.Y., Choi, R., Kim, U.K., Hwang, C.S., Lee, D., Hwang, H., and Jeong, J.K.: Effect of high-pressure oxygen annealing on negative bias illumination stress-induced instability of InGaZnO thin film transistors. Appl. Phys. Lett. 98(10), 103509 (2011).Google Scholar
Ryu, B., Noh, H-K., Choi, E-A., and Chang, K.: O-vacancy as the origin of negative bias illumination stress instability in amorphous In–Ga–Zn–O thin film transistors. Appl. Phys. Lett. 97(2), 022108 (2010).Google Scholar
Nathan, A., Lee, S., Jeon, S., and Robertson, J.: Amorphous oxide semiconductor TFTs for displays and imaging. J. Disp. Technol. PP(99), 1 (2013).Google Scholar
Kim, H-S., Jeon, S.H., Park, J.S., Kim, T.S., Son, K.S., Seon, J-B., Seo, S-J., Kim, S-J., Lee, E., and Chung, J.G.: Anion control as a strategy to achieve high-mobility and high-stability oxide thin-film transistors. Sci. Rep. 3, 1459 (2013).Google Scholar
Park, J.S., Kim, K., Park, Y.G., Mo, Y.G., Kim, H.D., and Jeong, J.K.: Novel ZrInZnO thin-film transistor with excellent stability. Adv. Mater. 21(3), 329 (2009).CrossRefGoogle Scholar
Hennek, J.W., Smith, J., Yan, A., Kim, M-G., Zhao, W., Dravid, V.P., Facchetti, A., and Marks, T.J.: Oxygen “getter” effects on microstructure and carrier transport in low temperature combustion-processed a-InXZnO (X = Ga, Sc, Y, La) transistors. J. Am. Chem. Soc. 135(29), 10729 (2013).Google Scholar
Chong, H.Y., Han, K.W., No, Y.S., and Kim, T.W.: Effect of the Ti molar ratio on the electrical characteristics of titanium-indium-zinc-oxide thin-film transistors fabricated by using a solution process. Appl. Phys. Lett. 99(16), 161908 (2011).CrossRefGoogle Scholar
Aikawa, S., Nabatame, T., and Tsukagoshi, K.: Effects of dopants in InOx-based amorphous oxide semiconductors for thin-film transistor applications. Appl. Phys. Lett. 103(17), 172105 (2013).CrossRefGoogle Scholar
Honglei, L., Mingyue, Q., and Qun, Z.: Influence of tungsten doping on the performance of indium-zinc-oxide thin-film transistors. IEEE Electron Device Lett. 34(10), 1268 (2013).Google Scholar
Aikawa, S., Darmawan, P., Yanagisawa, K., Nabatame, T., Abe, Y., and Tsukagoshi, K.: Thin-film transistors fabricated by low-temperature process based on Ga-and Zn-free amorphous oxide semiconductor. Appl. Phys. Lett. 102(10), 102101 (2013).Google Scholar
Park, J.C., Kim, S.W., Kim, C.J., and Lee, H-N.: The effects of gadolinium incorporation into indium–zinc–oxide thin-film transistors. IEEE Electron Device Lett. 33(6), 809 (2012).Google Scholar
Kim, S.J., Gunduz, B., Yoon, D.H., Kim, H.J., Al-Ghamdi, A.A., and Yakuphanoglu, F.: Photofield effect and photoresponse properties of the transparent oxide-based BaInZnO thin-film transistors. Sens. Actuators, A 193, 1 (2013).Google Scholar
Kim, S.J., Kim, D.L., Rim, Y.S., Jeong, W.H., Kim, D.N., Yoon, D.H., and Kim, H.J.: The formation of InZnO lattices incorporating Ba for thin-film transistors using a solution process. J. Cryst. Growth 326(1), 163 (2011).CrossRefGoogle Scholar
Banger, K.K., Peterson, R.L., Mori, K., Yamashita, Y., Leedham, T., and Sirringhaus, H.: High performance, low temperature solution-processed barium and strontium doped oxide thin film transistors. Chem. Mater. 26(2), 1195–1203 (2013).Google Scholar
Yoon, D.H., Kim, S.J., Jeong, W.H., Kim, D.L., Rim, Y.S., and Kim, H.J.: Investigation of solution-processed amorphous SrInZnO thin film transistors. J. Cryst. Growth 326(1), 171 (2011).Google Scholar
Chong, E., Chun, Y.S., and Lee, S.Y.: Amorphous silicon–indium–zinc oxide semiconductor thin film transistors processed below 150° C. Appl. Phys. Lett. 97(10), 102102 (2010).Google Scholar
Chong, E., Kim, S.H., and Lee, S.Y.: Role of silicon in silicon-indium-zinc-oxide thin-film transistor. Appl. Phys. Lett. 97(25), 252112 (2010).CrossRefGoogle Scholar
Choi, Y., Kim, G.H., Jeong, W.H., Bae, J.H., Kim, H.J., Hong, J-M., and Yu, J-W.: Carrier-suppressing effect of scandium in InZnO systems for solution-processed thin film transistors. Appl. Phys. Lett. 97(16), 162102 (2010).Google Scholar
Ting, C-C., Chang, S-P., Li, W-Y., and Wang, C-H.: Enhanced performance of indium zinc oxide thin film transistor by yttrium doping. Appl. Surf. Sci. 284, 397 (2013).CrossRefGoogle Scholar
Lee, Y-J., Kim, J-H., and Kang, J.: Characteristics of Y2O3-doped indium zinc oxide films grown by radio frequency magnetron co-sputtering system. Thin Solid Films 534, 599 (2013).Google Scholar
Shin, H.S., Kim, G.H., Jeong, W.H., Du Ahn, B., and Kim, H.J.: Electrical properties of yttrium-indium-zinc-oxide thin film transistors fabricated using the sol-gel process and various yttrium compositions. Jpn. J. Appl. Phys. 49(3), (2010).Google Scholar
Park, J.C., Kim, S.W., Kim, C.J., and Lee, H-N.: Low-temperature fabrication and characteristics of lanthanum indium zinc oxide thin-film transistors. IEEE Electron Device Lett. 33(5), 685 (2012).Google Scholar
Park, H-W., Kim, B-K., Park, J-S., and Chung, K-B.: Device performance and bias instability of Ta doped InZnO thin film transistor as a function of process pressure. Appl. Phys. Lett. 102(10), 102102 (2013).CrossRefGoogle Scholar
Lan, L., Xiong, N., Xiao, P., Li, M., Xu, H., Yao, R., Wen, S., and Peng, J.: Enhancement of bias and illumination stability in thin-film transistors by doping InZnO with wide-band-gap Ta2O5 . Appl. Phys. Lett. 102, 242102 (2013).Google Scholar
Kim, G.H., Jeong, W.H., Du Ahn, B., Shin, H.S., Kim, H.J., Kim, H.J., Ryu, M-K., Park, K-B., Seon, J-B., and Lee, S-Y.: Investigation of the effects of Mg incorporation into InZnO for high-performance and high-stability solution-processed thin film transistors. Appl. Phys. Lett. 96(16), 163506 (2010).Google Scholar
Koo, J., Kang, T., Kim, T., and Hong, J.: Electrical and optical characteristics of co-sputtered amorphous Ce-doped indium-zinc-oxide thin-film transistors. J. Korean Phys. Soc. 62(3), 527 (2013).CrossRefGoogle Scholar
Jang, K., Raja, J., Kim, J., Lee, Y., Kim, D., and Yi, J.: High field-effect mobility amorphous InSnZnO thin-film transistors with low carrier concentration and oxygen vacancy. Electron. Lett. 49(16), (2013).Google Scholar
Kerr, J.: CRC handbook of chemistry and physics 1999–2000: a ready-reference book of chemical and physical data. CRC Handbook of Chemistry and Physics, 81st ed.; CRC Press, Boca Raton, FL (2000).Google Scholar
Miura, K., Ueda, T., Nakano, S., Saito, N., Hara, Y., Sugi, K., Sakano, T., Yamaguchi, H., Amemiya, I., and Akimoto, K.: 4.1: Low-temperature-processed IGZO TFTs for flexible AMOLED with integrated gate driver circuits. In SID Symposium Digest of Technical Papers, Vol. 42, Wiley Online Library, New York, NY, 2011; p. 21.Google Scholar
Seo, J-S., Jeon, J-H., Hwang, Y.H., Park, H., Ryu, M., Park, S-H.K., and Bae, B-S.: Solution-processed flexible fluorine-doped indium zinc oxide thin-film transistors fabricated on plastic film at low temperature. Sci. Rep. 3, 2085 (2013).Google Scholar
Campet, G., Han, S.D., Wen, S.J., Manaud, J.P., Portier, J., Xu, Y., and Salardenne, J.: The electronic effect of Ti4+, Zr4+ and Ge4+ dopings upon the physical properties of In2O3 and Sn-doped In2O3 ceramics: Application to new highly-transparent conductive electrodes. Mater. Sci. Eng., B 19(3), 285 (1993).Google Scholar
Kang, S-B., Lim, J-W., Lee, S., Kim, J-J., and Kim, H-K.: Transparent indium oxide films doped with high Lewis acid strength Ge dopant for phosphorescent organic light-emitting diodes. J. Phys. D: Appl. Phys. 45(32), 325102 (2012).Google Scholar
Lee, H-M., Kang, S-B., Chung, K-B., and Kim, H-K.: Transparent and flexible amorphous In-Si-O films for flexible organic solar cells. Appl. Phys. Lett. 102(2), 021914 (2013).CrossRefGoogle Scholar
Kima, J.H., Kangb, S-B., Leeb, J-H., Shinb, Y-H., Shinb, H-S., Kwonc, D-G., Seong, T-Y., Parkc, Y., Nad, S-I., and Kimb, H-K.: Buffer and anode-integrated WO3-doped In2O3 electrodes for PEDOT: PSS-free organic photovoltaics. Org. Electron. 14, 1305 (2013).Google Scholar
Cho, D-Y., Chung, K-B., Na, S-I., and Kim, H-K.: Effect of Zr doping power on the electrical, optical and structural properties of In–Zr–O anodes for P3HT: PCBM thin-film organic solar cells. J. Phys. D: Appl. Phys. 46(29), 295305 (2013).Google Scholar
Lee, J-H. and Kim, H-K.: Transparent Ti-doped In2O3 films grown by linear facing target sputtering for organic solar cells. J. Korean Phys. Soc. 63(6), 1160 (2013).Google Scholar
Jeong, J-A., Jeon, Y-J., Kim, S-S., Kim, B.K., Chung, K-B., and Kim, H-K.: Simple brush-painting of Ti-doped In2O3 transparent conducting electrodes from nano-particle solution for organic solar cells. Sol. Energy Mater. Sol. Cells 122(0), 241 (2014).Google Scholar
Kim, D-J., Kim, B-S., and Kim, H-K.: Effect of thickness and substrate temperature on the properties of transparent Ti-doped In2O3 films grown by direct current magnetron sputtering. Thin Solid Films 547(0), 225 (2013).Google Scholar
Kim, J.H., Seong, T-Y., Na, S-I., Chung, K-B., Lee, H-M., and Kim, H-K.: Highly transparent Nb-doped indium oxide electrodes for organic solar cells. J. Vac. Sci. Technol., A 32(2), 021202 (2014).Google Scholar
Kim, J.H., Shin, Y.-H., Seong, T.Y., Na, S.I., and Kim, H.K.: Rapid thermal annealed WO3-doped In2O3 films for transparent electrodes in organic photovoltaics. J. Phys. D: Appl. Phys. 45(39), 395104 (2012).Google Scholar
Lim, J-W., Jun Kang, S., Lee, S., Kim, J-J., and Kim, H-K.: Transparent Ti-In-Sn-O multicomponent anodes for highly efficient phosphorescent organic light emitting diodes. J. Appl. Phys. 112(2) (2012).Google Scholar
Lee, K-S., Lim, J-W., Kim, H-K., Alford, T.L., and Jabbour, G.E.: Transparent conductive electrodes of mixed TiO2−x–indium tin oxide for organic photovoltaics. Appl. Phys. Lett. 100(21), 213302 (2012).Google Scholar
Kang, S-B., Lim, J-W., Na, S-I., and Kim, H-K.: Highly near-infrared transparent GeO2-doped In2O3 electrodes for bulk heterojunction organic solar cells. Sol. Energy Mater. Sol. Cells 107(0), 373 (2012).Google Scholar
Parthiban, S., Elangovan, E., Ramamurthi, K., Martins, R., and Fortunato, E.: Investigations on high visible to near infrared transparent and high mobility Mo doped In2O3 thin films prepared by spray pyrolysis technique. Sol. Energy Mater. Sol. Cells 94(3), 406 (2010).Google Scholar
Parthiban, S., Gokulakrishnan, V., Elangovan, E., Goncalves, G., Ramamurthi, K., Fortunato, E., and Martins, R.: High mobility and visible–near infrared transparent titanium doped indium oxide thin films produced by spray pyrolysis. Thin Solid Films 524, 268 (2012).Google Scholar
Zhang, Y.: Electronegativities of elements in valence states and their applications. 1. Electronegativities of elements in valence states. Inorg. Chem. 21(11), 3886 (1982).Google Scholar
Shannon, R.: Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr. Sect. A 32(5), 751 (1976).Google Scholar
Dean, J.A.: Lange's Handbook of Chemistry (McGraw-Hill, 1985).Google Scholar