Efficient one-pot synthesis of monodisperse alkyl-terminated colloidal germanium nanocrystals

Brief Communication


An efficient one-pot method for fabricating alkyl-capped germanium nanocrystals (Ge NCs) is reported. Ge NCs with a size of 3.9 ± 0.5 nm, are formed by co-reduction of germanium tetrachloride in the presence of n-butyltrichlorogermane, producing NCs with butyl-terminated surfaces. The advantage of this method is that it allows rapid synthesis and functionalisation of NCs with minimal post-synthetic purification requirements. TEM imaging showed that the Ge NCs are monodisperse and highly crystalline, while EDX and SAED confirmed the chemical identity and crystal phase of the NCs. FTIR and XPS confirmed that the Ge NCs were well passivated, with some oxidation of the nanocrystal surface. Optical spectroscopy of the NCs showed a strong absorbance in the UV region and an excitation wavelength dependent photoluminescence in the UV/violet. Time resolved photoluminescence measurements showed the presence of two nanosecond lifetime components, consistent with recombination of photogenerated excitons at low lying energy states present at the nanocrystal surface. Photoluminescence quantum yields were determined to be 37 %, one of the highest values reported for organically terminated Ge NCs.


Germanium Nanocrystals Synthesis Photoluminescence Quantum yield Semiconductors Nanoelectronics 



This work was supported by the European Commission under the FP7 Projects HYSENS (Grant agreement no. 263091) and CommonSense (Grant agreement no. 261809) and the Irish Higher Education Authority under the PRTLI programmes (Cycle 3 “Nanoscience” and Cycle 4 “INSPIRE”).

Supplementary material

11051_2014_2721_MOESM1_ESM.docx (1.5 mb)
Supplementary material 1 (DOCX 1,491 kb)


  1. Bottrill M, Green M (2011) Some aspects of quantum dot toxicity. Chem Commun 47:7039–7050. doi: 10.1039/c1cc10692a CrossRefGoogle Scholar
  2. Carolan D, Doyle H (2014) Size and emission color tuning in the solution phase synthesis of highly luminescent germanium nanocrystals. J Mater Chem C 2:3562–3568. doi: 10.1039/C4TC00319E CrossRefGoogle Scholar
  3. Council (2003) Directive 2002/95/EC on the restriction of the use of certain hazardous substances in electrical and electronic equipment. www.eur-lex.europa.eu
  4. Dasog M et al (2013) Chemical insight into the origin of red and blue photoluminescense arising from freestanding silicon nanocrystals. ACS Nano 7:2676–2685. doi: 10.1021/nn4000644 CrossRefGoogle Scholar
  5. Donega CdM (2011) Synthesis and properties of colloidal heteronanocrystals. Chem Soc Rev 40:1512–1546. doi: 10.1039/C0CS00055H CrossRefGoogle Scholar
  6. Fok E, Shih ML, Meldrum A, Veinot JGC (2004) Preparation of alkyl-surface functionalized germanium quantum dots via thermally initiated hydrogermylation. Chem Commun 4:386–387. doi: 10.1039/b314887d CrossRefGoogle Scholar
  7. Gaponik N, Hickey SG, Dorfs D, Rogach AL, Eychmüller A (2010) Progress in the light emission of colloidal semiconductor nanocrystals. Small 6:1364–1378. doi: 10.1002/smll.200902006 CrossRefGoogle Scholar
  8. Gerung H, Bunge SD, Boyle TJ, Brinker CJ, Han SM (2005) Anhydrous solution synthesis of germanium nanocrystals from the germanium(II) precursor Ge [N(SiMe3)2]2. Chem Commun 14:1914–1916. doi: 10.1039/b416066e CrossRefGoogle Scholar
  9. Ghosh B, Sakka Y, Shirahata N (2013) Efficient green-luminescent germanium nanocrystals. J Mater Chem 1:3747–3751. doi: 10.1039/c3ta01246h CrossRefGoogle Scholar
  10. Henderson EJ, Seino M, Puzzo DP, Ozin GA (2010) Colloidally stable germanium nanocrystals for photonic applications. ACS Nano 4:7683–7691. doi: 10.1021/nn102521k CrossRefGoogle Scholar
  11. Hoffman M, Veinot JGC (2012) Understanding the formation of elemental germanium by thermolysis of sol–gel derived organogermanium oxide polymers. Chem Mater 24:1283–1291. doi: 10.1021/cm2035129 CrossRefGoogle Scholar
  12. Holman ZC, Liu C-Y, Kortshagen UR (2010) Germanium and silicon nanocrystal thin-film field-effect transistors from solution. Nano Lett 10:2661–2666. doi: 10.1021/nl101413d CrossRefGoogle Scholar
  13. Lee DC, Pietryga JM, Robel I, Werder DJ, Schaller RD, Klimov VI (2009) Colloidal synthesis of infrared-emitting germanium nanocrystals. J Am Chem Soc 131:3436–3437. doi: 10.1021/ja809218s CrossRefGoogle Scholar
  14. Linehan K, Doyle H (2014) Size controlled synthesis of silicon nanocrystals using cationic surfactant templates. Small 10:584–590. doi: 10.1002/smll.201301189 CrossRefGoogle Scholar
  15. Lu XM, Korgel BA, Johnston KP (2005) Synthesis of germanium nanocrystals in high temperature supercritical CO2. Nanotechnology 16:S389–S394. doi: 10.1088/0957-4484/16/7/012 CrossRefGoogle Scholar
  16. Michalet X et al (2005) Quantum dots for live cells, in vivo imaging, and diagnostics. Science 307:538–544. doi: 10.1126/science.1104274 CrossRefGoogle Scholar
  17. Muthuswamy E, Iskandar AS, Amador MM, Kauzlarich SM (2012) Facile synthesis of germanium nanoparticles with size control: microwave versus conventional heating. Chem Mater 25:1416–1422. doi: 10.1021/cm302229b CrossRefGoogle Scholar
  18. Prabakar S, Shiohara A, Hanada S, Fujioka K, Yamamoto K, Tilley RD (2010) Size controlled synthesis of germanium nanocrystals by hydride reducing agents and their biological applications. Chem Mater 22:482–486. doi: 10.1021/cm9030599 CrossRefGoogle Scholar
  19. Rogach A (2008) Semiconductor nanocrystal quantum dots: synthesis, assembly, spectroscopy and applications. Springer, ViennaCrossRefGoogle Scholar
  20. Ruddy DA, Johnson JC, Smith ER, Neale NR (2010) Size and bandgap control in the solution-phase synthesis of near-infrared-emitting germanium nanocrystals. ACS Nano 4:7459–7466. doi: 10.1021/nn102728u CrossRefGoogle Scholar
  21. Schmid G (2010) Nanoparticles: from theory to application. Wiley, WeinheimCrossRefGoogle Scholar
  22. Shirahata N, Hirakawa D, Masuda Y, Sakka Y (2012) Size-dependent color tuning of efficiently luminescent germanium nanoparticles. Langmuir 29:7401–7410. doi: 10.1021/la303482s CrossRefGoogle Scholar
  23. Silverstein RM, Bassler GC, Morrill TC (1991) Spectrometric identification of organic compounds. Wiley, New YorkGoogle Scholar
  24. Socrates G (1980) Infrared characteristic group frequencies. Wiley, ChichesterGoogle Scholar
  25. Talapin DV, Lee J-S, Kovalenko MV, Shevchenko EV (2009) Prospects of colloidal nanocrystals for electronic and optoelectronic applications. Chem Rev 110:389–458. doi: 10.1021/cr900137k CrossRefGoogle Scholar
  26. Taylor BR, Kauzlarich SM, Delgado GR, Lee HWH (1999) Solution synthesis and characterization of quantum confined Ge nanoparticles. Chem Mater 11:2493–2500. doi: 10.1021/cm990203q CrossRefGoogle Scholar
  27. Vaughn DD II, Schaak RE (2013) Synthesis, properties and applications of colloidal germanium and germanium-based nanomaterials. Chem Soc Rev 42:2861–2879. doi: 10.1039/c2cs35364d CrossRefGoogle Scholar
  28. Wang J, Sun S, Peng F, Cao L, Sun L (2011) Efficient one-pot synthesis of highly photoluminescent alkyl-functionalised silicon nanocrystals. Chem Commun 47:4941–4943. doi: 10.1039/c1cc10573f CrossRefGoogle Scholar
  29. Warner JH, Tilley RD (2006) Synthesis of water-soluble photoluminescent germanium nanocrystals. Nanotechnology 17:3745–3749. doi: 10.1088/0957-4484/17/15/022 CrossRefGoogle Scholar
  30. Wilcoxon JP, Provencio PP, Samara GA (2001) Synthesis and optical properties of colloidal germanium nanocrystals. Phys Rev B 64:035417. doi: 10.1103/PhysRevB.64.035417 CrossRefGoogle Scholar
  31. Wilcoxon JP, Provencio PP, Samara GA (2007) Synthesis and optical properties of colloidal germanium nanocrystals. Phys Rev B 76:199904. doi: 10.1103/PhysRevB.76.199904 CrossRefGoogle Scholar
  32. Williams ATR, Winfield SA, Miller JN (1983) Relative fluorescence quantum yields using a computer-controlled luminescence spectrometer. Analyst 108:1067–1071. doi: 10.1039/an9830801067 CrossRefGoogle Scholar
  33. Winnick FM, Maysinger D (2013) Quantum dot cytotoxicity and ways to reduce it. Acc Chem Res 46:672–680. doi: 10.1021/ar3000585 CrossRefGoogle Scholar
  34. Wu J, Sun Y, Zou R, Song G, Chen Z, Wang C, Hu J (2011) One-step aqueous solution synthesis of Ge nanocrystals from GeO2 powders. CrystEngComm 13:3674–3677. doi: 10.1039/c1ce05191a CrossRefGoogle Scholar
  35. Xue D-J, Wang J-J, Wang Y-Q, Xin S, Guo Y-G, Wan L-J (2011) Facile synthesis of germanium nanocrystals and their application in organic-inorganic hybrid photodetectors. Adv Mater 23:3704–3707. doi: 10.1002/adma.201101436 CrossRefGoogle Scholar
  36. Ye L et al (2012) A pilot study in non-human primates shows no adverse response to intravenous injection of quantum dots. Nat Nanotechnol 7:453–458. doi: 10.1038/nnano.2012.74 CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  1. 1.Tyndall National InstituteUniversity College CorkCorkIreland

Personalised recommendations