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Can plasmonic Al nanoparticles improve absorption in triple junction solar cells?

Yang L, Pillai S, Green MA - Sci Rep (2015)

Bottom Line: The particle period, diameter and the thickness of the oxide layers were optimised for the sub-cells using simulations to achieve the lowest reflection and maximum external quantum efficiencies.Our results highlight the importance of proper reference comparison, and unlike previously published results, raise doubts regarding the effectiveness of Al plasmonic nanoparticles as a suitable front-side scattering medium for broadband efficiency enhancements when compared to standard single-layer antireflection coatings.However, by embedding the nanoparticles within the dielectric layer, they have the potential to perform better than an antireflection layer and provide enhanced response from both the sub-cells.

View Article: PubMed Central - PubMed

Affiliation: 1] Australian Centre for Advanced Photovoltaics, University of New South Wales, Sydney, NSW-2052, Australia [2] College of Applied Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China.

ABSTRACT
Plasmonic nanoparticles located on the illuminated surface of a solar cell can perform the function of an antireflection layer, as well as a scattering layer, facilitating light-trapping. Al nanoparticles have recently been proposed to aid photocurrent enhancements in GaAs photodiodes in the wavelength region of 400-900 nm by mitigating any parasitic absorption losses. Because this spectral region corresponds to the top and middle sub-cell of a typical GaInP/GaInAs/Ge triple junction solar cell, in this work, we investigated the potential of similar periodic Al nanoparticles placed on top of a thin SiO2 spacer layer that can also serve as an antireflection coating at larger thicknesses. The particle period, diameter and the thickness of the oxide layers were optimised for the sub-cells using simulations to achieve the lowest reflection and maximum external quantum efficiencies. Our results highlight the importance of proper reference comparison, and unlike previously published results, raise doubts regarding the effectiveness of Al plasmonic nanoparticles as a suitable front-side scattering medium for broadband efficiency enhancements when compared to standard single-layer antireflection coatings. However, by embedding the nanoparticles within the dielectric layer, they have the potential to perform better than an antireflection layer and provide enhanced response from both the sub-cells.

No MeSH data available.


(a) Calculated EQE spectra of the optimum SLAR-3JSC with and without Al NPs, also including a SiO2-based SLAR and MgF2/ZnS-based DLAR reference. (b-c) Calculated EQE spectra of SLAR-3JSC with and without Al NPs for the optimised case on (b) 25 nm and (c) 50 nm SiO2 SLAR.
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f8: (a) Calculated EQE spectra of the optimum SLAR-3JSC with and without Al NPs, also including a SiO2-based SLAR and MgF2/ZnS-based DLAR reference. (b-c) Calculated EQE spectra of SLAR-3JSC with and without Al NPs for the optimised case on (b) 25 nm and (c) 50 nm SiO2 SLAR.

Mentions: A large fraction of the scattered light from the Al NPs will be coupled into the substrate, and the exact fraction will be determined by the spacer layer thickness. It may be noted that using Al NPs on a standard thick SLAR will reduce the coupling of the scattered light into the absorber layer and thereby reduce the light absorption as discussed earlier. Because 3JSC with a SLAR of SiO2 yielded the overall maximum current when the thickness of SiO2 was 80 nm, we chose this structure as the reference for comparing the EQE spectra with Al-NP-incorporated 3JSC. Based on the optimised results, D100H50 with P375AR59 and P168AR56 were chosen for EQE to compare the performances of the top and middle sub-cells, respectively. As shown in Fig. 8(a), Al NPs with P375AR59 demonstrate higher EQE for the top cell than the SLAR reference at wavelengths below 450 nm, while Al NPs with P168AR56 show higher EQE for the middle cell at wavelengths of 600–900 nm.


Can plasmonic Al nanoparticles improve absorption in triple junction solar cells?

Yang L, Pillai S, Green MA - Sci Rep (2015)

(a) Calculated EQE spectra of the optimum SLAR-3JSC with and without Al NPs, also including a SiO2-based SLAR and MgF2/ZnS-based DLAR reference. (b-c) Calculated EQE spectra of SLAR-3JSC with and without Al NPs for the optimised case on (b) 25 nm and (c) 50 nm SiO2 SLAR.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490398&req=5

f8: (a) Calculated EQE spectra of the optimum SLAR-3JSC with and without Al NPs, also including a SiO2-based SLAR and MgF2/ZnS-based DLAR reference. (b-c) Calculated EQE spectra of SLAR-3JSC with and without Al NPs for the optimised case on (b) 25 nm and (c) 50 nm SiO2 SLAR.
Mentions: A large fraction of the scattered light from the Al NPs will be coupled into the substrate, and the exact fraction will be determined by the spacer layer thickness. It may be noted that using Al NPs on a standard thick SLAR will reduce the coupling of the scattered light into the absorber layer and thereby reduce the light absorption as discussed earlier. Because 3JSC with a SLAR of SiO2 yielded the overall maximum current when the thickness of SiO2 was 80 nm, we chose this structure as the reference for comparing the EQE spectra with Al-NP-incorporated 3JSC. Based on the optimised results, D100H50 with P375AR59 and P168AR56 were chosen for EQE to compare the performances of the top and middle sub-cells, respectively. As shown in Fig. 8(a), Al NPs with P375AR59 demonstrate higher EQE for the top cell than the SLAR reference at wavelengths below 450 nm, while Al NPs with P168AR56 show higher EQE for the middle cell at wavelengths of 600–900 nm.

Bottom Line: The particle period, diameter and the thickness of the oxide layers were optimised for the sub-cells using simulations to achieve the lowest reflection and maximum external quantum efficiencies.Our results highlight the importance of proper reference comparison, and unlike previously published results, raise doubts regarding the effectiveness of Al plasmonic nanoparticles as a suitable front-side scattering medium for broadband efficiency enhancements when compared to standard single-layer antireflection coatings.However, by embedding the nanoparticles within the dielectric layer, they have the potential to perform better than an antireflection layer and provide enhanced response from both the sub-cells.

View Article: PubMed Central - PubMed

Affiliation: 1] Australian Centre for Advanced Photovoltaics, University of New South Wales, Sydney, NSW-2052, Australia [2] College of Applied Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China.

ABSTRACT
Plasmonic nanoparticles located on the illuminated surface of a solar cell can perform the function of an antireflection layer, as well as a scattering layer, facilitating light-trapping. Al nanoparticles have recently been proposed to aid photocurrent enhancements in GaAs photodiodes in the wavelength region of 400-900 nm by mitigating any parasitic absorption losses. Because this spectral region corresponds to the top and middle sub-cell of a typical GaInP/GaInAs/Ge triple junction solar cell, in this work, we investigated the potential of similar periodic Al nanoparticles placed on top of a thin SiO2 spacer layer that can also serve as an antireflection coating at larger thicknesses. The particle period, diameter and the thickness of the oxide layers were optimised for the sub-cells using simulations to achieve the lowest reflection and maximum external quantum efficiencies. Our results highlight the importance of proper reference comparison, and unlike previously published results, raise doubts regarding the effectiveness of Al plasmonic nanoparticles as a suitable front-side scattering medium for broadband efficiency enhancements when compared to standard single-layer antireflection coatings. However, by embedding the nanoparticles within the dielectric layer, they have the potential to perform better than an antireflection layer and provide enhanced response from both the sub-cells.

No MeSH data available.