32 Fabrication of Charge-Transfer Complex Nanocrystals …
561
dianions in Cu-TCNQ nanocrystals to keep the charge balance between TCNQ and
excessive Cu, which was supported by Raman spectroscopy and STEM-EELS. Their
doped nanocrystals also showed a strong absorption peak in NIR region, whose
positions were strongly dependent on the content of TCNQ dianion.
The resulting doped Cu-TCNQ nanocrystals exhibited the electric field-induced
resistive switching. Especially, multiple switching was observed due to multistep
redox reaction of TCNQ dianions. This behavior was characteristic in doped CuTCNQ nanocrystals.
Acknowledgements The authors especially thank the late Emeritus Professor Hachiro Nakanishi
in Tohoku University (TU, Japan), Prof. Hitoshi Kasai (IMRAM, TU, Japan), Associate Prof.
Akito Masuhara in Yamagata University, Mr. Yuichiro Hayasaka (Technical staff, The Electron
Microscopy Center, TU, Japan), and D.Sc Kentaro Hiraishi, M.Sc. Satomi Matsuo and M.Sc. Reo
Hirose, B.Sc Fumika Matsushita (Dept. of Chemistry, Graduate School of Sci., TU, Japan at that
time) for their valuable scientific discussion and great experimental contributions. The present work
was supported in part by the Grants-in-Aid for Scientific Research (No. 23655183) from the Ministry
of Education, Culture, Sports, Science and Technology, Japan and by JSPS KAKENHI Grant
Number 26107002, Grant-in-Aid for Scientific Research on Innovative Areas “Photosynergetics”.
References
1. Tanaka J, Tanaka M, Kawai T, Takabe T, Maki O (1976) Electronic spectra and electronic
structure of TCNQ complex. Bull Chem Soc Jpn 49:2358–2373
2. Torrance JB (1979) The difference between metallic and insulating salts of tetracyanoquinodimethone (TCNQ): how to design an organic metal. Acc Chem Res 12:79–86
3. Nalwa HS (ed) (2000) Handbook of nanostructured materials and nanotechnology. Academic
Press, San Diego
4. Kasai H, Nalwa HS, Oikawa H, Okada S, Matsuda H, Minami N, Kakuta A, Ono K, Mukoh
A, Nakanishi H (1992) A novel preparation method of organic microcrystals. Jpn J Appl Phys
31:L1132–L1134
5. Kasai H, Oikawa H, Okada S, Nakanishi H (1998) Crystal growth of perylene microcrystals
in the reprecipitation method. Bull Chem Soc Jpn 71:2597–2601
6. Baba K, Kasai H, Okada S, Oikawa H, Nakanishi H (2000) Novel fabrication process of organic
microcrystals using microwave-irradiation. Jpn J Appl Phys 39:L1256–L1258
7. Ishii KU, Baba K, Wei Z, Kasai H, Nakanishi H, Okada S, Oikawa H (2006) Mass-production
of pigment nanocrystals by the reprecipitation method and their encapsulation. Mol Cryst Liq
Cryst 445:177/[467]–183[473]
8. Kaneko Y, Shimada S, Fukuda T, Kimura T, Yokoi H, Matsuda H, Onodera T, Kasai H, Okada
S, Oikawa H, Nakanishi H (2005) A novel method for fixing the anisotropic orientation of
dispersed organic nanocrystals in a magnetic field. Adv Mater 17:160–163
9. Baba K, Kasai H, Masuhara A, Okada S, Oikawa H, Nakanishi H (2007) Diacetylene nanowire
crystals prepared by reprecipitation/microwave-irradiation method. Jpn J Appl Phys 46:7558–
7561
10. Oyamada T, Tanaka H, Matsushige K, Sasabe H, Adachi C (2003) Switching effect in Cu:TCNQ
charge transfer-complex thin film by vacuum codeposition. Appl Phys Lett 83:1252–1254
11. Xiao K, Ivanov IN, Puretzky AA, Liu Z, Geohegan DB (2006) Directed integration of
tetracyanoquinodemethane-Cu organic nanowires into prefabricated device architectures. Adv
Mater 18:2184–2188
561
dianions in Cu-TCNQ nanocrystals to keep the charge balance between TCNQ and
excessive Cu, which was supported by Raman spectroscopy and STEM-EELS. Their
doped nanocrystals also showed a strong absorption peak in NIR region, whose
positions were strongly dependent on the content of TCNQ dianion.
The resulting doped Cu-TCNQ nanocrystals exhibited the electric field-induced
resistive switching. Especially, multiple switching was observed due to multistep
redox reaction of TCNQ dianions. This behavior was characteristic in doped CuTCNQ nanocrystals.
Acknowledgements The authors especially thank the late Emeritus Professor Hachiro Nakanishi
in Tohoku University (TU, Japan), Prof. Hitoshi Kasai (IMRAM, TU, Japan), Associate Prof.
Akito Masuhara in Yamagata University, Mr. Yuichiro Hayasaka (Technical staff, The Electron
Microscopy Center, TU, Japan), and D.Sc Kentaro Hiraishi, M.Sc. Satomi Matsuo and M.Sc. Reo
Hirose, B.Sc Fumika Matsushita (Dept. of Chemistry, Graduate School of Sci., TU, Japan at that
time) for their valuable scientific discussion and great experimental contributions. The present work
was supported in part by the Grants-in-Aid for Scientific Research (No. 23655183) from the Ministry
of Education, Culture, Sports, Science and Technology, Japan and by JSPS KAKENHI Grant
Number 26107002, Grant-in-Aid for Scientific Research on Innovative Areas “Photosynergetics”.
References
1. Tanaka J, Tanaka M, Kawai T, Takabe T, Maki O (1976) Electronic spectra and electronic
structure of TCNQ complex. Bull Chem Soc Jpn 49:2358–2373
2. Torrance JB (1979) The difference between metallic and insulating salts of tetracyanoquinodimethone (TCNQ): how to design an organic metal. Acc Chem Res 12:79–86
3. Nalwa HS (ed) (2000) Handbook of nanostructured materials and nanotechnology. Academic
Press, San Diego
4. Kasai H, Nalwa HS, Oikawa H, Okada S, Matsuda H, Minami N, Kakuta A, Ono K, Mukoh
A, Nakanishi H (1992) A novel preparation method of organic microcrystals. Jpn J Appl Phys
31:L1132–L1134
5. Kasai H, Oikawa H, Okada S, Nakanishi H (1998) Crystal growth of perylene microcrystals
in the reprecipitation method. Bull Chem Soc Jpn 71:2597–2601
6. Baba K, Kasai H, Okada S, Oikawa H, Nakanishi H (2000) Novel fabrication process of organic
microcrystals using microwave-irradiation. Jpn J Appl Phys 39:L1256–L1258
7. Ishii KU, Baba K, Wei Z, Kasai H, Nakanishi H, Okada S, Oikawa H (2006) Mass-production
of pigment nanocrystals by the reprecipitation method and their encapsulation. Mol Cryst Liq
Cryst 445:177/[467]–183[473]
8. Kaneko Y, Shimada S, Fukuda T, Kimura T, Yokoi H, Matsuda H, Onodera T, Kasai H, Okada
S, Oikawa H, Nakanishi H (2005) A novel method for fixing the anisotropic orientation of
dispersed organic nanocrystals in a magnetic field. Adv Mater 17:160–163
9. Baba K, Kasai H, Masuhara A, Okada S, Oikawa H, Nakanishi H (2007) Diacetylene nanowire
crystals prepared by reprecipitation/microwave-irradiation method. Jpn J Appl Phys 46:7558–
7561
10. Oyamada T, Tanaka H, Matsushige K, Sasabe H, Adachi C (2003) Switching effect in Cu:TCNQ
charge transfer-complex thin film by vacuum codeposition. Appl Phys Lett 83:1252–1254
11. Xiao K, Ivanov IN, Puretzky AA, Liu Z, Geohegan DB (2006) Directed integration of
tetracyanoquinodemethane-Cu organic nanowires into prefabricated device architectures. Adv
Mater 18:2184–2188