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Synthesis of CuInS2 quantum dots using polyetheramine as solvent.

Shei SC, Chiang WJ, Chang SJ - Nanoscale Res Lett (2015)

Bottom Line: An excess of group VI elements facilitated precipitation, whereas an excess of group I elements resulted in CuInS2 QDs with high photoluminescence quantum yield.Our results demonstrate that the band gap of the CuInS2 QDs is tunable with size as well as the composition of the reactant.We also determined some important physical parameters such as the band gaps and energy levels of this system, which are crucial for the application of CuInS2 nanocrystals.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, National University of Tainan, Tainan, 70005 Taiwan.

ABSTRACT
This paper presents a facile solvothermal method of synthesizing copper indium sulfide (CuInS2) quantum dots (QDs) via a non-coordinated system using polyetheramine as a solvent. The structural and optical properties of the resulting CuInS2 QDs were investigated using composition analysis, absorption spectroscopy, and emission spectroscopy. We employed molar ratios of I, III, and VI group elements to control the structure of CuInS2 QDs. An excess of group VI elements facilitated precipitation, whereas an excess of group I elements resulted in CuInS2 QDs with high photoluminescence quantum yield. The emission wavelength and photoluminescence quantum yield could also be modulated by controlling the composition ratio of Cu and In in the injection stock solution. An increase in the portion of S shifted the emission wavelength of the QDs to a shorter wavelength and increased the photoluminescence quantum yield. Our results demonstrate that the band gap of the CuInS2 QDs is tunable with size as well as the composition of the reactant. The photoluminescence quantum yield of the CuInS2 QDs ranged between 0.7% and 8.8% at 250°C. We also determined some important physical parameters such as the band gaps and energy levels of this system, which are crucial for the application of CuInS2 nanocrystals.

No MeSH data available.


TEM images of CIS QDs synthesized at temperatures of (a) 150°C, (b) 200°C, and (c) 250°C.
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Fig3: TEM images of CIS QDs synthesized at temperatures of (a) 150°C, (b) 200°C, and (c) 250°C.

Mentions: where D is the diameter of the crystallites forming the film, λ is the wavelength of the Cu Kα line, b is the FWHM in radians, and θ is the Bragg’s angle. Using the Debye-Scherrer equation, it was found that the average sizes of the CIS cores synthesized at 150°C, 200°C, and 250°C were 9.82, 10.41, and 13.68 nm, respectively. It was also found that XRD peak intensities increased with the synthesis temperature. This seems to suggest that CIS cores synthesized at higher temperatures could provide a better crystal quality. As shown in the TEM images in Figure 3, the sizes of the CIS QDs were about 10, 11, and 13 nm at solvothermal growth temperatures of 150°C, 200°C, and 250°C, respectively. The trend of TEM images is similar to the results of XRD measurements. In addition, their corresponding standard deviations of the size distribution are 0.98, 1.12, and 1.21 nm, respectively. The size of the CIS QDs increased with an increase in growth temperature, which is consistent with the XRD and PL data, as shown in Figures 1 and 2. Since the shape of the QD seems not circular, we cannot control of the QD shape regarding to different growth conditions. But, the compositions of the QD were measured and shown as Cu:In:S = 25.9:24.8:49.3.Figure 3


Synthesis of CuInS2 quantum dots using polyetheramine as solvent.

Shei SC, Chiang WJ, Chang SJ - Nanoscale Res Lett (2015)

TEM images of CIS QDs synthesized at temperatures of (a) 150°C, (b) 200°C, and (c) 250°C.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385220&req=5

Fig3: TEM images of CIS QDs synthesized at temperatures of (a) 150°C, (b) 200°C, and (c) 250°C.
Mentions: where D is the diameter of the crystallites forming the film, λ is the wavelength of the Cu Kα line, b is the FWHM in radians, and θ is the Bragg’s angle. Using the Debye-Scherrer equation, it was found that the average sizes of the CIS cores synthesized at 150°C, 200°C, and 250°C were 9.82, 10.41, and 13.68 nm, respectively. It was also found that XRD peak intensities increased with the synthesis temperature. This seems to suggest that CIS cores synthesized at higher temperatures could provide a better crystal quality. As shown in the TEM images in Figure 3, the sizes of the CIS QDs were about 10, 11, and 13 nm at solvothermal growth temperatures of 150°C, 200°C, and 250°C, respectively. The trend of TEM images is similar to the results of XRD measurements. In addition, their corresponding standard deviations of the size distribution are 0.98, 1.12, and 1.21 nm, respectively. The size of the CIS QDs increased with an increase in growth temperature, which is consistent with the XRD and PL data, as shown in Figures 1 and 2. Since the shape of the QD seems not circular, we cannot control of the QD shape regarding to different growth conditions. But, the compositions of the QD were measured and shown as Cu:In:S = 25.9:24.8:49.3.Figure 3

Bottom Line: An excess of group VI elements facilitated precipitation, whereas an excess of group I elements resulted in CuInS2 QDs with high photoluminescence quantum yield.Our results demonstrate that the band gap of the CuInS2 QDs is tunable with size as well as the composition of the reactant.We also determined some important physical parameters such as the band gaps and energy levels of this system, which are crucial for the application of CuInS2 nanocrystals.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, National University of Tainan, Tainan, 70005 Taiwan.

ABSTRACT
This paper presents a facile solvothermal method of synthesizing copper indium sulfide (CuInS2) quantum dots (QDs) via a non-coordinated system using polyetheramine as a solvent. The structural and optical properties of the resulting CuInS2 QDs were investigated using composition analysis, absorption spectroscopy, and emission spectroscopy. We employed molar ratios of I, III, and VI group elements to control the structure of CuInS2 QDs. An excess of group VI elements facilitated precipitation, whereas an excess of group I elements resulted in CuInS2 QDs with high photoluminescence quantum yield. The emission wavelength and photoluminescence quantum yield could also be modulated by controlling the composition ratio of Cu and In in the injection stock solution. An increase in the portion of S shifted the emission wavelength of the QDs to a shorter wavelength and increased the photoluminescence quantum yield. Our results demonstrate that the band gap of the CuInS2 QDs is tunable with size as well as the composition of the reactant. The photoluminescence quantum yield of the CuInS2 QDs ranged between 0.7% and 8.8% at 250°C. We also determined some important physical parameters such as the band gaps and energy levels of this system, which are crucial for the application of CuInS2 nanocrystals.

No MeSH data available.