Wavelength conversion effect-assisted dye-sensitized solar cells for enhanced solar light harvesting

Abstract

aIn the present study, an enhanced solar light harvesting strategy based on the wavelength conversion effect is suggested in dye-sensitized solar cells (DSSCs). Incorporating β-NaYF4:Yb 3+ ,Er 3+ phosphor microcrystals as a component of the DSSCs enables wavelength conversion from infrared to visible light, which maximizes the absorption of visible light by the C106 organometallic dye and produces excess current, thus enhancing the quantum efficiency. It is demonstrated that the photocurrent density generated is increased by the wavelength conversion effect of the phosphor material. The introduction of up-converting β-NaYF4:Yb 3+ ,Er 3+ phosphor microcrystals dispersed in an iodide electrolyte and the use of an additional phosphor reflecting film increases the overall solar-to-electrical energy conversion efficiency (η) from 9.02% of reference DSSCs to 9.48 and 10.76%, respectively. DSSCs with phosphors contained in both the iodide electrolyte solution as well as an additional phosphor reflecting film show a highly enhanced overall efficiency of 10.90%. Herein, a strategy for effective wavelength conversion is investigated for enhanced solar light harvesting, and the results of the study contribute the most viable strategy for achieving maximum utilization of the solar spectrum.

Preparation of Multishell-Structured NaYF4:Yb,Tm,Nd@NaYF4:Yb,Nd@SiO2@ZnO Nanospheres with Effective NIR-Induced Photocatalytic Activity

“…10−13 Conversely, photon upconversion is a process of combining two or more low energy photons to generate one higher energy excited state, effectively shortening the wavelength of the light emitted upon irradiation. 14,15 It can be predicted that the synthesis of composite photocatalyst based on upconversion materials can broaden the light response range to IR region, which not only improves the catalytic activity of semiconductors, but also improves the utilization efficiency of solar energy. Therefore, the design of photocatalysts constructed by lanthanide (Ln 3+ )-doped UCNPs and semiconductors, such as NaYF 4 :Yb,Tm@TiO 2 , NaYF 4 :Yb,Tm@ ZnO, NaYF 4 :Tm/BiVO 4 , NaYF 4 :Yb,Er@TiO 2 −Ag 6 Si 2 O 7 , Bi-OBr:Yb,Er/AgBr, and CaLa 2 (MoO 4 ) 4 :Er,Yb@TiO 2 , has recently attracted the attention of researchers.…”

“…The wavelength conversion of the solar spectrum by one or more phosphor materials is a promising solution to achieve this goal, which includes three types of photon luminescence conversion processes, namely upconversion, downconversion, and downshifting . One single high energy photon splits into two lower energy photons in the downconversion process, similarly, the downshifting is a process in which the substrate absorbs high energy photons and then re-emits lower energy photons. − Conversely, photon upconversion is a process of combining two or more low energy photons to generate one higher energy excited state, effectively shortening the wavelength of the light emitted upon irradiation. , It can be predicted that the synthesis of composite photocatalyst based on upconversion materials can broaden the light response range to IR region, which not only improves the catalytic activity of semiconductors, but also improves the utilization efficiency of solar energy. Therefore, the design of photocatalysts constructed by lanthanide (Ln 3+ )-doped UCNPs and semiconductors, such as NaYF 4 :Yb,Tm@TiO 2 , NaYF 4 :Yb,Tm@ZnO, NaYF 4 :Tm/BiVO 4 , NaYF 4 :Yb,Er@TiO 2 –Ag 6 Si 2 O 7 , BiOBr:Yb,Er/AgBr, and CaLa 2 (MoO 4 ) 4 :Er,Yb@TiO 2 , has recently attracted the attention of researchers. − On the basis of the above works, plasmon-enhanced broadband catalysts composed of both plasmonic and upconversion nanocomponents with wide bandgap semiconductor, such as NaYF 4 :Yb,Tm@TiO 2 /Ag and NaYF 4 :Yb,Er,Tm@TiO 2 –Au, , have also been reported.…”

A dual-functional NaLuF4:Yb3+/Er3+ material for enhancing photon harvesting in dye-sensitized solar cells

“…Chunze Yuan et al 24 explored the use of colloidal UC nanocrystals as an energy relay material for photovoltaic devices and found that the UC nanocrystals of small size can serve as a scattering material to increase the light absorption capability of cells. Kim et al 25 demonstrated enhanced efficiency from 9.02% of reference DSSCs to 10.76% by upconverting b-NaYF 4 :Yb 3+ /Er 3+ phosphor microcrystals as an additional phosphor-reecting lm. b-NaLuF 4 is a very excellent upconversion material, 26,27 and not yet reported in solar cells.…”