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Ternary SnS(2-x)Se(x) Alloys Nanosheets and Nanosheet Assemblies with Tunable Chemical Compositions and Band Gaps for Photodetector Applications.

Yu J, Xu CY, Li Y, Zhou F, Chen XS, Hu PA, Zhen L - Sci Rep (2015)

Bottom Line: The variation tendency of band gap was also confirmed by first-principles calculations.The photoelectrochemical measurements indicate that the performance of ternary SnS(2-x)Se(x) alloys depends on their band structures and morphology characteristics.Furthermore, SnS(2-x)Se(x) photodetectors present high photoresponsivity with a maximum of 35 mA W(-1) and good light stability in a wide range of spectral response from ultraviolet to visible light, which renders them promising candidates for a variety of optoelectronic applications.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.

ABSTRACT
Ternary metal dichalcogenides alloys exhibit compositionally tunable optical properties and electronic structure, and therefore, band gap engineering by controllable doping would provide a powerful approach to promote their physical and chemical properties. Herein we obtained ternary SnS(2-x)Se(x) alloys with tunable chemical compositions and optical properties via a simple one-step solvothermal process. Raman scattering and UV-vis-NIR absorption spectra reveal the composition-related optical features, and the band gaps can be discretely modulated from 2.23 to 1.29 eV with the increase of Se content. The variation tendency of band gap was also confirmed by first-principles calculations. The change of composition results in the difference of crystal structure as well as morphology for SnS(2-x)Se(x) solid solution, namely, nanosheets assemblies or nanosheet. The photoelectrochemical measurements indicate that the performance of ternary SnS(2-x)Se(x) alloys depends on their band structures and morphology characteristics. Furthermore, SnS(2-x)Se(x) photodetectors present high photoresponsivity with a maximum of 35 mA W(-1) and good light stability in a wide range of spectral response from ultraviolet to visible light, which renders them promising candidates for a variety of optoelectronic applications.

No MeSH data available.


Raman spectra of SnS2−xSex alloys with different x values.
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f3: Raman spectra of SnS2−xSex alloys with different x values.

Mentions: Raman spectra were used to examine the composition-dependent vibration modes of SnS2−xSex ternary alloys. Figure 3 presents the normalized Raman spectra of as-prepared SnS2−xSex samples with the increase of Se content. For SnS2 NSs32, only A1g(S−Sn) mode was detected at 313.4 cm−1. The absence of intra-layer Eg(S−Sn) can be ascribed to the weak rejection of Rayleigh scattered radiation or the choice principle for scattering geometry in SnS2 nanosheets1834. In contrast, two prominent vibration peaks in SnSe2 plates assigned to A1g(Se−Sn) mode at 177.4 cm−1 and Eg(Se−Sn) mode at 99.2 cm−1 are observed. Because of the low concentration of Se in SnS1.66Se0.34 alloy, the vibration peaks of SnSe2-like modes are not strong enough to be observed. Similarly, the peaks of SnS2-like modes are also not obvious in SnS0.44Se1.56 with low S content. As shown in Fig. 3, the intensity of SnS2-like A1g mode would decrease until completely disappear, while the SnSe2-like A1g and Eg modes come into appearance and gradually enhance with increasing Se content. The peak patterns of pure material (SnS232 or SnSe2) are simple and sharp, while that of the alloys are broad and complex. In addition, all the vibration modes shift to low frequency. The transitions of molecular vibration modes exhibit strong dependence on increasing Se concentrations in the composition-dependent SnS2−xSex alloys.


Ternary SnS(2-x)Se(x) Alloys Nanosheets and Nanosheet Assemblies with Tunable Chemical Compositions and Band Gaps for Photodetector Applications.

Yu J, Xu CY, Li Y, Zhou F, Chen XS, Hu PA, Zhen L - Sci Rep (2015)

Raman spectra of SnS2−xSex alloys with different x values.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663750&req=5

f3: Raman spectra of SnS2−xSex alloys with different x values.
Mentions: Raman spectra were used to examine the composition-dependent vibration modes of SnS2−xSex ternary alloys. Figure 3 presents the normalized Raman spectra of as-prepared SnS2−xSex samples with the increase of Se content. For SnS2 NSs32, only A1g(S−Sn) mode was detected at 313.4 cm−1. The absence of intra-layer Eg(S−Sn) can be ascribed to the weak rejection of Rayleigh scattered radiation or the choice principle for scattering geometry in SnS2 nanosheets1834. In contrast, two prominent vibration peaks in SnSe2 plates assigned to A1g(Se−Sn) mode at 177.4 cm−1 and Eg(Se−Sn) mode at 99.2 cm−1 are observed. Because of the low concentration of Se in SnS1.66Se0.34 alloy, the vibration peaks of SnSe2-like modes are not strong enough to be observed. Similarly, the peaks of SnS2-like modes are also not obvious in SnS0.44Se1.56 with low S content. As shown in Fig. 3, the intensity of SnS2-like A1g mode would decrease until completely disappear, while the SnSe2-like A1g and Eg modes come into appearance and gradually enhance with increasing Se content. The peak patterns of pure material (SnS232 or SnSe2) are simple and sharp, while that of the alloys are broad and complex. In addition, all the vibration modes shift to low frequency. The transitions of molecular vibration modes exhibit strong dependence on increasing Se concentrations in the composition-dependent SnS2−xSex alloys.

Bottom Line: The variation tendency of band gap was also confirmed by first-principles calculations.The photoelectrochemical measurements indicate that the performance of ternary SnS(2-x)Se(x) alloys depends on their band structures and morphology characteristics.Furthermore, SnS(2-x)Se(x) photodetectors present high photoresponsivity with a maximum of 35 mA W(-1) and good light stability in a wide range of spectral response from ultraviolet to visible light, which renders them promising candidates for a variety of optoelectronic applications.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.

ABSTRACT
Ternary metal dichalcogenides alloys exhibit compositionally tunable optical properties and electronic structure, and therefore, band gap engineering by controllable doping would provide a powerful approach to promote their physical and chemical properties. Herein we obtained ternary SnS(2-x)Se(x) alloys with tunable chemical compositions and optical properties via a simple one-step solvothermal process. Raman scattering and UV-vis-NIR absorption spectra reveal the composition-related optical features, and the band gaps can be discretely modulated from 2.23 to 1.29 eV with the increase of Se content. The variation tendency of band gap was also confirmed by first-principles calculations. The change of composition results in the difference of crystal structure as well as morphology for SnS(2-x)Se(x) solid solution, namely, nanosheets assemblies or nanosheet. The photoelectrochemical measurements indicate that the performance of ternary SnS(2-x)Se(x) alloys depends on their band structures and morphology characteristics. Furthermore, SnS(2-x)Se(x) photodetectors present high photoresponsivity with a maximum of 35 mA W(-1) and good light stability in a wide range of spectral response from ultraviolet to visible light, which renders them promising candidates for a variety of optoelectronic applications.

No MeSH data available.