The mismatch between the photovoltaic(PV)cells absorption and the solar irradiance on earth is one of the major limitations towards more efficient PV energy conversion.This aspect was addressed by downshifting the sol...The mismatch between the photovoltaic(PV)cells absorption and the solar irradiance on earth is one of the major limitations towards more efficient PV energy conversion.This aspect was addressed by downshifting the solar irradiance on Earth through luminescent down-shifting layers based on lanthanidedoped surface-functionalized ionosilicas(ISs)embedded in poly(methyl methacrylate)(PMMA)coated on the surface of commercial Si-based PV cells.The IS-PMMA hybrid materials exhibit efficient solar radiation harvesting(spectral overlap of^9.5×10^19 photons/(s·m2))and conversion(quantum yield^52%).The direct solar radiation and the down-shifted radiation are partially guided and lost through total internal reflection to the layer edges being unavailable for PV conversion of the coated PV cell.By tuning the down-shifting layer thickness,it also acts as luminescent solar concentrator enabling the collection of the guided radiation by flexible PV cells applied on the borders of the down-shifting layer leading to an enhancement of the PV energy conversion from^5%(in the case of the single-use of the luminescent down-shifting layer)to^13%comparing with the bare PV cell.The overall electrical output of the device resulted in an absolute external quantum efficiency increase of^32%for the optimized Eu^3+-based films in the UV spectral region(compared with the bare PV device,which is among the best values reported so far).展开更多
The optical properties ofZnO nanoparticles （NPs） fabricated by three different methods were studied by the UV-excited continuous wave photoluminescence in order to estimate their down-shifting （DS） efficiency. Suc...The optical properties ofZnO nanoparticles （NPs） fabricated by three different methods were studied by the UV-excited continuous wave photoluminescence in order to estimate their down-shifting （DS） efficiency. Such a luminescent layer modifies the incident solar radiation via emitting wavelengths better matching the spectral response of the underlying photosensitive device （photodiode）, thereby increasing its efficiency. Some of the studied ZnO NPs were subsequently deposited on the front side of commercial silicon photodiodes and the external quantum efficiency （EQE） characteristics of the final devices were measured. Through comparison of the photodiode＇s EQE characteristics before and after the deposition of the ZnO NPs layer, it was concluded that for the photodiode with a low UV sensitivity （about 8%）, the ZnO luminescent layer produces a down-shifting effect and the EQE in the UV and blue range improves by 16.6%, while for the photodiodes with a higher initial UV sensitivity （about 50%）, the EQE in this range decreases with the ZnO layer thickness, due to the effects competing with DS, like the diminution of the ZnO layer transmittance and an increasing diffusion.展开更多
In this study, we propose the fabrication of monolithic crystalline silicon solar cells with Tb^(3+) and Yb^(3+)-doped silicon nitride(SiN_x) layers by low-cost screen-printing methods. The performances of c-Si solar ...In this study, we propose the fabrication of monolithic crystalline silicon solar cells with Tb^(3+) and Yb^(3+)-doped silicon nitride(SiN_x) layers by low-cost screen-printing methods. The performances of c-Si solar cells can be enhanced by rare-earth ions doped SiN_x layers via the mechanism of spectrum conversion.These SiN_x doped and codoped thin films were deposited by reactive magnetron co-sputtering and integrated as the antireflection coating layers in c-Si solar cells. The characterizations of SiN_x, SiN_x:Tb^(3+) tand SiN_x:Tb^(3+)-Yb^(3+) thin films were conducted by means of photoluminescence, Rutherford backscattering spectroscopy, Ellipsometry spectroscopy and Fourier transform infrared measurements. Their composition and refractive index was optimized to obtain good anti-reflection coating layer for c-Si solar cells.Transmission electron microscopy performs the uniform coatings on the textured emitter of c-Si solar cells. After the metallization process, we demonstrate monolithic c-Si solar cells with spectrum conversion layers, which lead to a relative increase by 1.34% in the conversion efficiency.展开更多
Organic solar cells(OSCs)in terms of power conversion efficiency(PCE)and operational lifetime have made remarkable progress during the last decade by improving the active layer materials and introducing new interlayer...Organic solar cells(OSCs)in terms of power conversion efficiency(PCE)and operational lifetime have made remarkable progress during the last decade by improving the active layer materials and introducing new interlayers.The newly developed wide bandgap organic donor and low bandgap acceptor molecules covered the absorption from the visible to the near-infrared region.Whereas the incident high energy region(UV)is not in favor of OSCs.Its absorption causes thermalization losses and photoinduced degradation,which hinders the PCE and lifetime of OSCs.Recently,lanthanide and non-lanthanide-based down-conversion(DC)materials have been introduced,which can effectively convert the high-energy photons(UV)to low-energy photons(visible)and resolve the spectral mismatch losses that limit the absorption of OSCs in high energy incident spectrum.Furthermore,the DC materials also protect the OSCs from UV-induced degradation.The DC materials were also proposed to cross the Shockley-Queisser efficiency limit of the solar cell.In this review,the need for DC materials and their processing method for OSCs have been thoroughly discussed.However,the main emphasis has been given to developing lanthanides and non-lanthanides-based DC materials for OSCs,their applications,and their impact on photovoltaic device performance,stability,and future perspectives.展开更多
基金Project supported by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership in the frame of Operational Competitiveness and Internationalization Programme(projects UIDB/50011/2020&UIDP/50011/2020,UID/EEA/50008/2020,UID/QUI/50006/2019,CENTRO-01-0145-FEDER-030186,CENTRO-01-0145-FEDER-000005,Pest-OE/QUI/UI0616/2014,POCI-01-0145-FEDER-016884,PTDC/CTM-NAN/0956/2014,UID/QUI/00686/2016,UID/QUI/00686/2018,UID/QUI/00686/2019 and NORTE-01-0145-FEDER-030858)。
文摘The mismatch between the photovoltaic(PV)cells absorption and the solar irradiance on earth is one of the major limitations towards more efficient PV energy conversion.This aspect was addressed by downshifting the solar irradiance on Earth through luminescent down-shifting layers based on lanthanidedoped surface-functionalized ionosilicas(ISs)embedded in poly(methyl methacrylate)(PMMA)coated on the surface of commercial Si-based PV cells.The IS-PMMA hybrid materials exhibit efficient solar radiation harvesting(spectral overlap of^9.5×10^19 photons/(s·m2))and conversion(quantum yield^52%).The direct solar radiation and the down-shifted radiation are partially guided and lost through total internal reflection to the layer edges being unavailable for PV conversion of the coated PV cell.By tuning the down-shifting layer thickness,it also acts as luminescent solar concentrator enabling the collection of the guided radiation by flexible PV cells applied on the borders of the down-shifting layer leading to an enhancement of the PV energy conversion from^5%(in the case of the single-use of the luminescent down-shifting layer)to^13%comparing with the bare PV cell.The overall electrical output of the device resulted in an absolute external quantum efficiency increase of^32%for the optimized Eu^3+-based films in the UV spectral region(compared with the bare PV device,which is among the best values reported so far).
基金the financial support from the Chinese Scientific Council(CSC)
文摘The optical properties ofZnO nanoparticles （NPs） fabricated by three different methods were studied by the UV-excited continuous wave photoluminescence in order to estimate their down-shifting （DS） efficiency. Such a luminescent layer modifies the incident solar radiation via emitting wavelengths better matching the spectral response of the underlying photosensitive device （photodiode）, thereby increasing its efficiency. Some of the studied ZnO NPs were subsequently deposited on the front side of commercial silicon photodiodes and the external quantum efficiency （EQE） characteristics of the final devices were measured. Through comparison of the photodiode＇s EQE characteristics before and after the deposition of the ZnO NPs layer, it was concluded that for the photodiode with a low UV sensitivity （about 8%）, the ZnO luminescent layer produces a down-shifting effect and the EQE in the UV and blue range improves by 16.6%, while for the photodiodes with a higher initial UV sensitivity （about 50%）, the EQE in this range decreases with the ZnO layer thickness, due to the effects competing with DS, like the diminution of the ZnO layer transmittance and an increasing diffusion.
基金Project supported by Ministry of Science and Technology,Taiwan(MOST 105-2911-I-259-501)the French Agence Nationale de Recherche through the GENESE Project(ANR-13-BSS09-0020-01)the French Ministry of Research through the ORCHID Project(33572XF)
文摘In this study, we propose the fabrication of monolithic crystalline silicon solar cells with Tb^(3+) and Yb^(3+)-doped silicon nitride(SiN_x) layers by low-cost screen-printing methods. The performances of c-Si solar cells can be enhanced by rare-earth ions doped SiN_x layers via the mechanism of spectrum conversion.These SiN_x doped and codoped thin films were deposited by reactive magnetron co-sputtering and integrated as the antireflection coating layers in c-Si solar cells. The characterizations of SiN_x, SiN_x:Tb^(3+) tand SiN_x:Tb^(3+)-Yb^(3+) thin films were conducted by means of photoluminescence, Rutherford backscattering spectroscopy, Ellipsometry spectroscopy and Fourier transform infrared measurements. Their composition and refractive index was optimized to obtain good anti-reflection coating layer for c-Si solar cells.Transmission electron microscopy performs the uniform coatings on the textured emitter of c-Si solar cells. After the metallization process, we demonstrate monolithic c-Si solar cells with spectrum conversion layers, which lead to a relative increase by 1.34% in the conversion efficiency.
基金SPECIFIC Innovation and Knowledge Centre,Grant/Award Number:EP/N020863/1Council of Scientific&Industrial Research,Grant/Award Number:31/1 (0494)/2018-EMR-1。
文摘Organic solar cells(OSCs)in terms of power conversion efficiency(PCE)and operational lifetime have made remarkable progress during the last decade by improving the active layer materials and introducing new interlayers.The newly developed wide bandgap organic donor and low bandgap acceptor molecules covered the absorption from the visible to the near-infrared region.Whereas the incident high energy region(UV)is not in favor of OSCs.Its absorption causes thermalization losses and photoinduced degradation,which hinders the PCE and lifetime of OSCs.Recently,lanthanide and non-lanthanide-based down-conversion(DC)materials have been introduced,which can effectively convert the high-energy photons(UV)to low-energy photons(visible)and resolve the spectral mismatch losses that limit the absorption of OSCs in high energy incident spectrum.Furthermore,the DC materials also protect the OSCs from UV-induced degradation.The DC materials were also proposed to cross the Shockley-Queisser efficiency limit of the solar cell.In this review,the need for DC materials and their processing method for OSCs have been thoroughly discussed.However,the main emphasis has been given to developing lanthanides and non-lanthanides-based DC materials for OSCs,their applications,and their impact on photovoltaic device performance,stability,and future perspectives.
