Solution synthesis and optical properties of SnTe nanocrystals ...
SUPPORTING INFORMATION
Solution synthesis and optical properties of SnTe nanocrystals Ying Xu†, Najeh Al-Salim,‡ Justin M. Hodgkiss†, Richard D. Tilley†*
Experimental Section I. Reagents and Materials Tin bromide (SnBr2), tellurium (Te) powder (99.8%, 200 mesh) and sodium borohydride (98%) were purchased from Aldrich. Triethanolamine (TEA) was purchased from Pure Science. N,Ndimethylformamide (DMF, maximum 0.01% H2O) was purchased from Scharlau. All the chemicals were used as received.
II. Synthesis of SnTe nanoparticles: Without further heat treatment (reflux): In a typical synthesis, SnBr2 (0.1130g, 0.4 mmol) was dissolved in a mixture solution of 2 mL TEA and 20 mL of DMF, followed by heating to 50 °C. After that, 2 mL of 0.1 M oxygen-free telluride solution, prepared by the reaction of tellurium powder with NaBH4, was injected rapidly into the reaction mixture. The resulting SnTe nanoparticles were separated out via centrifugation and washed rapidly in DMF for 3-4 times and stored in a suitable solvent for characterization. All the syntheses were performed under Argon atmosphere.
With further heat treatment (reflux 2 min): In a typical synthesis, SnBr2 (0.1130g, 0.4 mmol) was dissolved in a mixture solution of 2 mL TEA and 20 mL of DMF, followed by heating to 50 °C. 2 mL of 0.1 M oxygen-free telluride solution, prepared by the reaction of tellurium powder with NaBH4, was injected rapidly into the reaction mixture. After that, the mixture was refluxed for 2 minutes. The resulting SnTe nanoparticles were separated out via centrifugation and washed rapidly in DMF for 3-4 times and stored in a suitable solvent for characterization. All the syntheses were performed under Argon atmosphere. With 0.5 mL TEA (reflux 2 min): In a typical synthesis, SnBr2 (0.1130g, 0.4mmol) was dissolved in a mixture solution of 0.5 mL TEA and 20 mL of DMF, followed by heating to 50 °C. 2 mL of 0.1 M oxygen-free telluride solution, prepared by the reaction of tellurium powder with NaBH4, was injected rapidly into the reaction mixture. After that, the mixture was refluxed for 2 minutes. The resulting SnTe nanoparticles were separated out via centrifugation and washed rapidly in DMF for 3-4 times and stored in a suitable solvent for characterization. All the syntheses were performed under Argon atmosphere.
With 4 mL TEA (reflux 2 min): In a typical synthesis, SnBr2 (0.1130g, 0.4 mmol) was dissolved in a mixture solution of 4 mL TEA and 20 mL of DMF, followed by heating to 50 °C. 2 mL of 0.1 M oxygen-free telluride solution, prepared by the reaction of tellurium powder with NaBH4, was injected rapidly into the reaction mixture. After that, the mixture was refluxed for 2 minutes. The resulting SnTe nanoparticles were separated out via centrifugation and washed rapidly in DMF for 3-4 times and stored in a suitable solvent for characterization. All the syntheses were performed under Argon atmosphere.
III. Characterization. Transmission Electron Microscopy (TEM), energy dispersive X-ray analysis (EDX) and selected area electron diffraction (SAED) pattern were performed on JEOL 2010 microscope. Powder Xray diffraction was carried out with a Philips PW 1700 XRD equipped with a graphite monochromatized Co Kα radiation anode. FTIR spectra were recorded under vacuum with a Bomem DA8 FTIR spectrophotometer. CaF2 discs (25 mm in diameter) were used to support sample films for the FTIR measurements.
SI 1. SAED pattern for SnTe nanoparticles prepared in the presence of 2 mL of TEA with further heat treatment.
SI 2. Energy Dispersive X-ray (EDX) spectrum of SnTe nanoparticles.
SI 3. (a) TEM image of SnTe nanoparticles prepared in the presence of 0.5 mL of TEA, (b) the corresponding size distribution histogram for the nanoparticles. (c) TEM image of SnTe nanoparticles prepared in the presence of 4 mL of TEA, (d) the corresponding size distribution histogram for the nanoparticles
Solution synthesis and optical properties of SnTe nanocrystals Ying Xu†, Najeh Al-Salim,‡ Justin M. Hodgkiss†, Richard D. Tilley†*
Experimental Section I. Reagents and Materials Tin bromide (SnBr2), tellurium (Te) powder (99.8%, 200 mesh) and sodium borohydride (98%) were purchased from Aldrich. Triethanolamine (TEA) was purchased from Pure Science. N,Ndimethylformamide (DMF, maximum 0.01% H2O) was purchased from Scharlau. All the chemicals were used as received.
II. Synthesis of SnTe nanoparticles: Without further heat treatment (reflux): In a typical synthesis, SnBr2 (0.1130g, 0.4 mmol) was dissolved in a mixture solution of 2 mL TEA and 20 mL of DMF, followed by heating to 50 °C. After that, 2 mL of 0.1 M oxygen-free telluride solution, prepared by the reaction of tellurium powder with NaBH4, was injected rapidly into the reaction mixture. The resulting SnTe nanoparticles were separated out via centrifugation and washed rapidly in DMF for 3-4 times and stored in a suitable solvent for characterization. All the syntheses were performed under Argon atmosphere.
With further heat treatment (reflux 2 min): In a typical synthesis, SnBr2 (0.1130g, 0.4 mmol) was dissolved in a mixture solution of 2 mL TEA and 20 mL of DMF, followed by heating to 50 °C. 2 mL of 0.1 M oxygen-free telluride solution, prepared by the reaction of tellurium powder with NaBH4, was injected rapidly into the reaction mixture. After that, the mixture was refluxed for 2 minutes. The resulting SnTe nanoparticles were separated out via centrifugation and washed rapidly in DMF for 3-4 times and stored in a suitable solvent for characterization. All the syntheses were performed under Argon atmosphere. With 0.5 mL TEA (reflux 2 min): In a typical synthesis, SnBr2 (0.1130g, 0.4mmol) was dissolved in a mixture solution of 0.5 mL TEA and 20 mL of DMF, followed by heating to 50 °C. 2 mL of 0.1 M oxygen-free telluride solution, prepared by the reaction of tellurium powder with NaBH4, was injected rapidly into the reaction mixture. After that, the mixture was refluxed for 2 minutes. The resulting SnTe nanoparticles were separated out via centrifugation and washed rapidly in DMF for 3-4 times and stored in a suitable solvent for characterization. All the syntheses were performed under Argon atmosphere.
With 4 mL TEA (reflux 2 min): In a typical synthesis, SnBr2 (0.1130g, 0.4 mmol) was dissolved in a mixture solution of 4 mL TEA and 20 mL of DMF, followed by heating to 50 °C. 2 mL of 0.1 M oxygen-free telluride solution, prepared by the reaction of tellurium powder with NaBH4, was injected rapidly into the reaction mixture. After that, the mixture was refluxed for 2 minutes. The resulting SnTe nanoparticles were separated out via centrifugation and washed rapidly in DMF for 3-4 times and stored in a suitable solvent for characterization. All the syntheses were performed under Argon atmosphere.
III. Characterization. Transmission Electron Microscopy (TEM), energy dispersive X-ray analysis (EDX) and selected area electron diffraction (SAED) pattern were performed on JEOL 2010 microscope. Powder Xray diffraction was carried out with a Philips PW 1700 XRD equipped with a graphite monochromatized Co Kα radiation anode. FTIR spectra were recorded under vacuum with a Bomem DA8 FTIR spectrophotometer. CaF2 discs (25 mm in diameter) were used to support sample films for the FTIR measurements.
SI 1. SAED pattern for SnTe nanoparticles prepared in the presence of 2 mL of TEA with further heat treatment.
SI 2. Energy Dispersive X-ray (EDX) spectrum of SnTe nanoparticles.
SI 3. (a) TEM image of SnTe nanoparticles prepared in the presence of 0.5 mL of TEA, (b) the corresponding size distribution histogram for the nanoparticles. (c) TEM image of SnTe nanoparticles prepared in the presence of 4 mL of TEA, (d) the corresponding size distribution histogram for the nanoparticles
