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Electrical Properties of Ga2O3:Sn/CIGS Hetero-junction

Published online by Cambridge University Press:  11 March 2014

Kenji Kikuchi
Affiliation:
NHK Science and Technology Research Laboratories, 1-10-11, Kinuta, Setagaya-ku, Tokyo, 157–8510, Japan Graduate School of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama, 223–8522, Japan
Shigeyuki Imura
Affiliation:
NHK Science and Technology Research Laboratories, 1-10-11, Kinuta, Setagaya-ku, Tokyo, 157–8510, Japan
Kazunori Miyakawa
Affiliation:
NHK Science and Technology Research Laboratories, 1-10-11, Kinuta, Setagaya-ku, Tokyo, 157–8510, Japan
Misao Kubota
Affiliation:
NHK Science and Technology Research Laboratories, 1-10-11, Kinuta, Setagaya-ku, Tokyo, 157–8510, Japan
Eiji Ohta
Affiliation:
Graduate School of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama, 223–8522, Japan
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Abstract

There is an increased need for highly sensitive imaging devices to develop high resolution and high speed image sensors. Incident light intensity per pixel of image sensors is getting lower because the pixel resolution and frame rate of image sensors are becoming higher. We investigated the feasibility of using a photoconductor with tin-doped gallium oxide (Ga2O3:Sn)/Cu(In,Ga)Se2 (CIGS) hetero-junction for visible light image sensors. CIGS chalcopyrite thin films have great potential for improving the sensitivity of image sensors and CIGS chalcopyrite semiconductors have both a high absorption coefficient and high quantum efficiency. Moreover, the band gap can be adjusted for visible light. We applied Ga2O3 as an n-type semiconductor layer and a hole-blocking layer to CIGS thin film to reduce the dark current. The experimental results revealed that dark current was drastically reduced due to the application of Ga2O3 thin film, and an avalanche multiplication phenomenon was observed at an applied voltage of over 6 V. However, non-doped Ga2O3/CIGS hetero-junction only had sensitivity in the ultraviolet light region because their depletion region was almost completely spread throughout the Ga2O3 layer due to the low carrier density of the Ga2O3 layer. Therefore, we used Ga2O3:Sn for the n-type layer to increase carrier density. As a result, the depletion region shifted to the CIGS film and the cells had sensitivity in all visible regions. These results indicate that Ga2O3:Sn/CIGS hetero-junction are feasible for visible light photoconductors.

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Articles
Copyright
Copyright © Materials Research Society 2014 

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References

REFERENCES

Ito, T., IEEE Asian Solid State Circuits Conference (A-SSCC) 8 (2010).Google Scholar
Tell, B., Shay, J. L., and Kasper, H. M., Phys. Rev. B 4 2463 (1971).10.1103/PhysRevB.4.2463CrossRefGoogle Scholar
Nakada, T., Furumi, K., and Kunioka, A., IEEE Transactions of Electron Devices 46(10), 2093 (1999).10.1109/16.792002CrossRefGoogle Scholar
Tanaka, K., Kosugi, M., Ando, F., Ushiki, T., Usui, H., and Sato, K., Jpn. J. Appl. Phys. Suppl. 32, 113 (1993).10.7567/JJAPS.32S3.113CrossRefGoogle Scholar
Kikuchi, K., Ohkawa, Y., Miyakawa, K., Matsubara, T., Tanioka, K., Kubota, M., and Egami, N., Phys. Stat. Sol. (c) 8(9), 2800 (2011).Google Scholar
Ueda, N., Hosono, H., Waseda, R., and Kawazoe, H., Appl. Phys. Lett. 70(26), 3561 (1997).10.1063/1.119233CrossRefGoogle Scholar
Hanna, G., Jasenek, A., Rau, U., and Schock, H. W., Thin Solid Films, 387, 71 (2001).10.1016/S0040-6090(00)01710-7CrossRefGoogle Scholar
Herberholz, R., Nadenau, V., Ruhle, U., Koble, C., W.Schock, H., and Dimmler, B., Solar Energy Materials and Solar Cells 49, 227 (1997).10.1016/S0927-0248(97)00199-2CrossRefGoogle Scholar
Minemoto, T., Matusi, T., Takakura, H., Hamakawa, Y., Negami, T., Hashimoto, Y., Uenoyama, T., and Kitagawa, M., Solar Energy Materials & Solar Cells 67, 83 (2001).10.1016/S0927-0248(00)00266-XCrossRefGoogle Scholar
Tanioka, K., Yamazaki, J., Shidara, K., Taketoshi, K., Kawamura, T., Ishioka, S., and Takasaki, Y., IEEE Electron Device Lett. 8, 392 (1987).10.1109/EDL.1987.26671CrossRefGoogle Scholar
Orita, M., Hiramatsu, H., Ohta, H., Hirano, M., and Hosono, H., Thin Solid Films 411, 134 (2002).10.1016/S0040-6090(02)00202-XCrossRefGoogle Scholar
Zhang, Y., Yan, J., Zhao, G. and Xie, W., Physica B, 405, 3899 (2010).10.1016/j.physb.2010.06.024CrossRefGoogle Scholar