Upconversion is a photon-management process especially suited to water-splitting cells that exploit wide-bandgap photocatalysts. Currently, such catalysts cannot utilize 95% of the available solar photons. We demonstrate here that the energy-conversion yield for a standard photocatalytic water-splitting device can be enhanced under solar irradiance by using a low-power upconversion system that recovers part of the unutilized incident sub-bandgap photons. The upconverter is based on a sensitized triplet-triplet annihilation mechanism (sTTA-UC) obtained in a dye-doped elastomer and boosted by a fluorescent nanocrystal/polymer composite that allows for broadband light harvesting. The complementary and tailored optical properties of these materials enable efficient upconversion at subsolar irradiance, allowing the realization of the first prototype water-splitting cell assisted by solid-state upconversion. In our proof-of concept device the increase of the performance is 3.5%, which grows to 6.3% if concentrated sunlight (10 sun) is used. Our experiments show how the sTTA-UC materials can be successfully implemented in technologically relevant devices while matching the strict requirements of clean-energy production.

Monguzzi, A., Oertel, A., Braga, D., Riedinger, A., Kim, D., Knüsel, P., et al. (2017). Photocatalytic Water-Splitting Enhancement by Sub-Bandgap Photon Harvesting. ACS APPLIED MATERIALS & INTERFACES, 9(46), 40180-40186 [10.1021/acsami.7b10829].

Photocatalytic Water-Splitting Enhancement by Sub-Bandgap Photon Harvesting

Monguzzi, Angelo
;
BRAGA, DANIELE;BIANCHI, ALBERTO;Mauri, Michele;Simonutti, Roberto;Meinardi, Francesco
2017

Abstract

Upconversion is a photon-management process especially suited to water-splitting cells that exploit wide-bandgap photocatalysts. Currently, such catalysts cannot utilize 95% of the available solar photons. We demonstrate here that the energy-conversion yield for a standard photocatalytic water-splitting device can be enhanced under solar irradiance by using a low-power upconversion system that recovers part of the unutilized incident sub-bandgap photons. The upconverter is based on a sensitized triplet-triplet annihilation mechanism (sTTA-UC) obtained in a dye-doped elastomer and boosted by a fluorescent nanocrystal/polymer composite that allows for broadband light harvesting. The complementary and tailored optical properties of these materials enable efficient upconversion at subsolar irradiance, allowing the realization of the first prototype water-splitting cell assisted by solid-state upconversion. In our proof-of concept device the increase of the performance is 3.5%, which grows to 6.3% if concentrated sunlight (10 sun) is used. Our experiments show how the sTTA-UC materials can be successfully implemented in technologically relevant devices while matching the strict requirements of clean-energy production.
Articolo in rivista - Articolo scientifico
fluorescent nanocrystals; nanocomposites; photon managing; triplet-triplet annihilation; upconversion;
fluorescent nanocrystals; nanocomposites; photon managing; triplet−triplet annihilation; upconversion
English
2017
9
46
40180
40186
reserved
Monguzzi, A., Oertel, A., Braga, D., Riedinger, A., Kim, D., Knüsel, P., et al. (2017). Photocatalytic Water-Splitting Enhancement by Sub-Bandgap Photon Harvesting. ACS APPLIED MATERIALS & INTERFACES, 9(46), 40180-40186 [10.1021/acsami.7b10829].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/176324
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