Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light

Abstract

The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents and hence higher efficiencies. Photon up-conversion by way of triplet-triplet annihilation (TTA-UC) is an attractive technique for using these otherwise wasted low energy photons to produce photocurrent, while not interfering with the photoanodic performance in a deleterious manner. Further to this, TTA-UC has a number of features, distinct from other reported photon up-conversion technologies, which renders it particularly suitable for coupling with DSC technology. In this work, a proven high performance TTA-UC system, comprising a palladium porphyrin sensitizer and rubrene emitter, is combined with a high performance DSC (utilizing the organic dye D149) in an integrated device. The device shows an enhanced response to sub-bandgap light over the absorption range of the TTA-UC sub-unit resulting in the highest figure of merit for up-conversion assisted DSC performance to date. Video LinkThe video component of this article can be found at

Highly efficient photochemical upconversion in a quasi-solid organogel

“…silicon (a-Si:H) and dye-sensitized cells. [2][3][4]50,51 Application of the present gel-phase upconvertor is therefore immediately possible, and we expect that the results will be identical to the comparable liquid solution. For application to a-Si:H or DSCs, we have previously employed a red-absorbing sensitizer, such as tetrakisquinoxalinoporphyrin palladium(II), and an orangeemitter, namely rubrene.…”

“…For application to a-Si:H or DSCs, we have previously employed a red-absorbing sensitizer, such as tetrakisquinoxalinoporphyrin palladium(II), and an orangeemitter, namely rubrene. [2][3][4]50,51 Further, the efficiency of the present system could be improved by employing a lower viscosity solvent. We used tetralin, because its boiling point was such that it made safely achieving the temperature required, for dissolution of the gelator, rather facile.…”

Determinants of the efficiency of photon upconversion by triplet–triplet annihilation in the solid state: zinc porphyrin derivatives in PVA

“…Non-coherent photon upconversion (NCPU) by triplet-triplet annihilation (TTA) is one of the most promising of these avenues of research. [1][2][3][4][5][6][7][8][9][10][11][12][13] In the usual case, NCPU-TTA consists of a series of photophysical events beginning with the harvesting of low-energy photons by a sensitizer that undergoes efficient intersystem crossing (ISC) to its lowest triplet state. This is then followed by triplet−triplet energy transfer (TTET) to a non-absorbing but highly fluorescent acceptor with a long-lived triplet state and a large S1 -T1 energy gap.…”

HDL biodistribution and brain receptors in zebrafish, using HDLs as vectors for targeting endothelial cells and neural progenitors

“…Chromogenic ISH on whole adult brains was performed as described 48 , 59 . Briefly, brains were rehydrated and washed with PTW (0.1% Tween 20, PBS buffer; pH 7.4).…”

“…Cholesterol transporters Abca1 and Abcg1 42 , as well as Scarb1 (SR-BI) ( www.ensembl.org ) and Cd36 43 , have been found in zebrafish. In addition, in contrast to mammals that have only two main cerebral neurogenic niches during adulthood and a limited capacity to repair the brain, adult zebrafish exhibit numerous neurogenic niches across their brain and an important ability for healing 41 , 44 – 48 . Consequently, more and more studies investigate the impact of metabolic disorders, such as hyperglycemia and obesity, on brain homeostasis and plasticity 29 , 31 , 49 , 50 .…”