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Enhancement of the blue photoluminescence intensity for the porous silicon with HfO2 filling into microcavities.

Jiang R, Du X, Sun W, Han Z, Wu Z - Sci Rep (2015)

Bottom Line: On one hand, HfO2 contributes to the light emission with the transitions of the defect levels for oxygen vacancy.On the other hand, the special filling-into-microcavities structure of HfO2 leads to the presence of ferroelectricity, which greatly enhances the blue emission from porous silicon.Since both HfO2 and Si are highly compatible with Si-based electronic industry, combined the low-cost and convenient process, the HfO2-filled porous Si shows a promising application prospect.

View Article: PubMed Central - PubMed

Affiliation: School of Physics, Shandong University, Jinan 250100, China.

ABSTRACT
With HfO2 filled into the microcavities of the porous single-crystal silicon, the blue photoluminescence was greatly enhanced at room temperature. On one hand, HfO2 contributes to the light emission with the transitions of the defect levels for oxygen vacancy. On the other hand, the special filling-into-microcavities structure of HfO2 leads to the presence of ferroelectricity, which greatly enhances the blue emission from porous silicon. Since both HfO2 and Si are highly compatible with Si-based electronic industry, combined the low-cost and convenient process, the HfO2-filled porous Si shows a promising application prospect.

No MeSH data available.


Schematic diagram for the light emission from HfO2 by the transitions in the energy levels of defect states.
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f6: Schematic diagram for the light emission from HfO2 by the transitions in the energy levels of defect states.

Mentions: The blue subpeaks from HfO2, i.e., and , are located at 3.3 eV (375 nm) and 3.0 eV (430 nm), respectively. Correspondingly, the red subpeaks from HfO2, i.e., and , are located at 1.7 eV (750 nm) and 1.4 eV (860 nm), respectively. The above results are consistent with the previous reports that the PL bands of HfO2 are located at 1.4–1.8 eV (690–890 nm) and at 2.1–3.5 eV (354–590 nm)293235. We have checked the strongest excitation energy during PL measurement, it is found that 4.7 eV is most favaroubale, which should correspond to the dominating defects lies at 4.7 eV above the valence band. Therefore, it could be reasonable that the irradiation in HfO2 dielectric was probably from the band-to-band transition due to the oxygen vacancy defect levels. The transition process may as below: The carrier first is excited to the defect states of 4.7 eV above EV and then relaxed to the defect states of 3.3 and 3.0 eV, with the energy difference of 1.7 and 1.4 eV which corresponding to the red emission and . Then, the relaxed carriers were recombined in the valence band with a luminance with the blue emission 3.3 and 3.0 eV, which are consistent with the blue subpeaks of and , respectively. The energy level of the defect states are schematically shown in Fig. 6.


Enhancement of the blue photoluminescence intensity for the porous silicon with HfO2 filling into microcavities.

Jiang R, Du X, Sun W, Han Z, Wu Z - Sci Rep (2015)

Schematic diagram for the light emission from HfO2 by the transitions in the energy levels of defect states.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4622088&req=5

f6: Schematic diagram for the light emission from HfO2 by the transitions in the energy levels of defect states.
Mentions: The blue subpeaks from HfO2, i.e., and , are located at 3.3 eV (375 nm) and 3.0 eV (430 nm), respectively. Correspondingly, the red subpeaks from HfO2, i.e., and , are located at 1.7 eV (750 nm) and 1.4 eV (860 nm), respectively. The above results are consistent with the previous reports that the PL bands of HfO2 are located at 1.4–1.8 eV (690–890 nm) and at 2.1–3.5 eV (354–590 nm)293235. We have checked the strongest excitation energy during PL measurement, it is found that 4.7 eV is most favaroubale, which should correspond to the dominating defects lies at 4.7 eV above the valence band. Therefore, it could be reasonable that the irradiation in HfO2 dielectric was probably from the band-to-band transition due to the oxygen vacancy defect levels. The transition process may as below: The carrier first is excited to the defect states of 4.7 eV above EV and then relaxed to the defect states of 3.3 and 3.0 eV, with the energy difference of 1.7 and 1.4 eV which corresponding to the red emission and . Then, the relaxed carriers were recombined in the valence band with a luminance with the blue emission 3.3 and 3.0 eV, which are consistent with the blue subpeaks of and , respectively. The energy level of the defect states are schematically shown in Fig. 6.

Bottom Line: On one hand, HfO2 contributes to the light emission with the transitions of the defect levels for oxygen vacancy.On the other hand, the special filling-into-microcavities structure of HfO2 leads to the presence of ferroelectricity, which greatly enhances the blue emission from porous silicon.Since both HfO2 and Si are highly compatible with Si-based electronic industry, combined the low-cost and convenient process, the HfO2-filled porous Si shows a promising application prospect.

View Article: PubMed Central - PubMed

Affiliation: School of Physics, Shandong University, Jinan 250100, China.

ABSTRACT
With HfO2 filled into the microcavities of the porous single-crystal silicon, the blue photoluminescence was greatly enhanced at room temperature. On one hand, HfO2 contributes to the light emission with the transitions of the defect levels for oxygen vacancy. On the other hand, the special filling-into-microcavities structure of HfO2 leads to the presence of ferroelectricity, which greatly enhances the blue emission from porous silicon. Since both HfO2 and Si are highly compatible with Si-based electronic industry, combined the low-cost and convenient process, the HfO2-filled porous Si shows a promising application prospect.

No MeSH data available.