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Enhanced light harvesting in dye‐sensitized solar cells enabled by TiO 2 :Er 3+ , Yb 3+ upconversion phosphor particles as solar spectral converter and light scattering medium
Author(s) -
Luo Xiuting,
Cha Jeong Geun,
Fu Guiming,
Lee Hyung Woo,
Kim Soo Hyung
Publication year - 2021
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.6879
Subject(s) - photon upconversion , dye sensitized solar cell , materials science , energy conversion efficiency , phosphor , visible spectrum , optoelectronics , doping , chemistry , electrolyte , electrode
Summary To improve the light‐harvesting properties of dye‐sensitized solar cells (DSSCs), light from the ultraviolet (UV), visible, and infrared (IR) regions of the solar energy should be effectively harvested. Ru(II)‐based dyes play a key role in harvesting energy from parts of the UV and visible regions but cannot absorb IR light. A strategy for improving the DSSC efficiency is to employ upconversion phosphors (UCPs) that can convert IR into visible light. In this study, using TiO 2 :Er 3+ , Yb 3+ UCPs fabricated via a simple aerosol process and calcination, we examine the effects of upconversion and light scattering of UCPs added into the TiO 2 thin‐film‐based photoelectrode on DSSC efficiency. Under IR irradiation, the fabricated TiO 2 :Er 3+ , Yb 3+ UCPs emit visible light with emission peaks at 529, 550, and 650 nm. The power conversion efficiency ( PCE ) of the DSSCs is significantly improved by adding the optimized amount of UCPs with the average size of 500 nm in the TiO 2 nanoparticles (NPs) matrix with the average size of 25 nm due to light upconversion and scattering effects. However, the addition of excess UCPs deteriorates the DSSCs efficiency owing to the rapid recombination between photogenerated electrons and holes and the increased interfaces between UCPs and TiO 2 . These results suggest that the light‐harvesting efficiency of DSSCs in the IR region can be enhanced by employing the optimal amount of large‐sized UCPs as light upconversion and scattering medium in the TiO 2 thin‐film‐based photoelectrode.