Commercial Upconversion Phosphors with High Light Harvesting: A Superior Candidate for High‐Performance Dye‐Sensitized Solar Cells. Issue 18 (17th July 2019)

• Record Type: Journal Article
• Authors: Mao, Xiaoli; Yu, Jianguo; Xu, Jun; Wan, Lei; Yang, Yuanjun; Lin, Hui; Xu, Jinzhang; Zhou, Ru
• Is Part Of: Physica status solidi. Volume 216:Issue 18(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-07-17
• Subjects: dye-sensitized solar cells -- upconversion phosphors -- light scattering; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201900382
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : An efficient photoanode for dye‐sensitized solar cells (DSSCs) requires a particular feature of high light harvesting. Herein, a promising new type of upconversion phosphors (UCPs)‐TiO2 composite photoanode for enhanced light harvesting in DSSCs is designed, resorting to the use of commercial upconversion β‐NaYF4 :Yb 3+, Er 3+ phosphors with submicrometer‐sized irregular shapes. The excellent light scattering coupled with an additional near‐infrared light‐harvesting effect of upconversion β‐NaYF4 :Yb 3+, Er 3+ nanoparticles contribute to the greatly enhanced light harvesting. Meanwhile, the incorporation of such UCPs into photoanodes involves the aggravation of charge recombination at the interface of photoanode–electrolyte; this unfavorable influence is minimized via the coating of a thin TiO2 layer on UCPs. The successful balance of the competition between such positive and negative impacts results in an optimal weight ratio of 15% for UCPs/TiO2 ; the corresponding DSSC delivers a power conversion efficiency (PCE) up to 7.17%, much higher than that of 5.45% for the bare TiO2 nanoparticle‐based device. This study highlights the great contributions of commercial β‐NaYF4 :Yb 3+, Er 3+ UCPs to the efficient light harvesting for enhanced photovoltaic performance of DSSCs. Abstract : A new type of efficient composite photoanode for dye‐sensitized solar cells is fabricated by incorporating commercial upconversion β‐NaYF4 :Yb 3+, Er 3+ phosphors with submicrometer‐sized irregular shapes into conventional TiO2 films. Benefited from enhanced light harvesting due to the excellent light scattering and the upconversion of near‐infrared into visible light, an overall power conversion efficiency of 7.17% is achieved.