Name: integrating a triplet-triplet annihilation up-conversion system to enhance dye-sensitized solar cell response to sub-bandgap light
Uploaded: 2014-09-12T15:00:00
Description: Watch this Scientific Journal Video about Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light at JoVE.com

A.N. acknowledges contributions from the Australian Renewable Energy Agency (ARENA) and the Australian National Fabrication Facility (ANFF). This research project is funded by the Australian Solar Institute (6-F020 and A-023), with contributions from The New South Wales Government and the University of Sydney. Aspects of this research were supported under Australian Research Council&#8217;s Discovery Projects funding scheme (DP110103300). Equipment was purchased with support from the Australian Research Council (LE0668257).

1. DSC Fabrication
1.1. Working Electrode Preparation
<ol>
	<li>Clean one whole sheet of F:SnO2 coated glass (110 mm &#215; 110 mm &#215; 2.3 mm, &#60;8 &#937;/&#9633;) by sonication sequentially in soapy water, then acetone and finally ethanol (10 min each).</li>
	<li>Deposit a dense layer of TiO2 following the steps below:
	<ol>
		<li>Dry glass using compressed air and heat glass to 450 &#176;C on hotplate (conductive side up).</li>
		<li>Dilute Titanium diisopropoxide b...

<ol>
	<li>O'Regan, B., Gr&#228;tzel, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+low-cost,+high-efficiency+solar-cell+based+on+dye-sensitized+colloidal+TiO2+films.">A low-cost, high-efficiency solar-cell based on dye-sensitized colloidal TiO2 films.</a> Nature. 353, 737-740 (1991).</li><li>Gr&#228;tzel, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photoelectrochemical+cells.">Photoelectrochemical cells.</a> Nature. 414 (6861), 338-344 (2001).</li><li>Hagfeldt, A., Boschloo, G., Sun, L., Kloo, L., Pettersson, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dye-Sensitized+Solar+Cells.">Dye-Sensitized Solar Cells.</a> Chem. Rev. 110 (11), 6595-6663 (2010).</li><li>Tayebjee, M. J. Y., Hirst, L. 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Mater. 9 (1), 31-35 (2010).</li><li>Nattestad, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dye-Sensitized+Solar+Cell+with+Integrated+Triplet-Triplet+Annihilation+Upconversion+System.">Dye-Sensitized Solar Cell with Integrated Triplet-Triplet Annihilation Upconversion System.</a> J. Phys. Chem. Lett. 4 (12), 2073-2078 (2013).</li><li>Liu, M., Lu, Y., Xie, Z. B., Chow, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhancing+Near-Infrared+Solar+Cell+Response+Using+Upconverting+Transparent+Ceramics.">Enhancing Near-Infrared Solar Cell Response Using Upconverting Transparent Ceramics.</a> Sol. Energ. Mat. Sol. C. 95, 800-803 (2011).</li><li>Shan, G. B., Demopolous, G. 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This protocol provides a means to achieve photon up-conversion enhanced DSC and detail on how to correctly measure such a device. The FoM allows for the simple calculation of anticipated &#916;JSC improvements to be expected at different light intensities, including at 1 sun. The values shown here are invariant with light intensity (inset of Figure 4), as per expectation when the system is below its saturation threshold33. With the FoM, we can standardize the enhancement effect of T...

Dye-sensitized solar cells (DSCs) have been proclaimed as a promising concept in affordable solar energy collection1-3. In spite of this enthusiasm, widespread commercialization has yet to occur. A number of reasons have been put forward for this, with one pressing issue being the relatively high energy of the absorption onset, limiting the achievable light harvesting efficiency of these devices4. Although this can be overcome, lowering the absorption onset is typically accompanied by a drop in open circuit voltage, which disproportionately erodes any gains in current density5, 6.
The general operation of DSCs involves electron transfer from a photoexcited dye to a semiconductor (typically TiO2), followed by the regeneration of the oxidized dye by a redox mediator. Both these processes appear to require substantial driving forces (potential) in order to proceed with high efficiency7. With such significant inherent losses, it becomes obvious that the optimal absorption onset for these devices is reasonably high in energy. Similar problems exist for organic photovoltaics (OPV), due once again to the large chemical driving forces required for effective charge separation. Accordingly, predictions of upper solar-to-electric conversion efficiency limits to single junction devices based on both of these technologies involve absorbers with wide (effective) band gaps4.
In order to overcome the light harvesting issue raised above, a number of approaches have been taken. This includes the &#8216;third generation&#8217;8 approaches of tandem structures9, 10 and photon upconversion11-14.
Recently11 we reported an integrated device composed of a DSC working and counter electrode, with a triplet-triplet annihilation based up-conversion (TTA-UC) system incorporated into the structure. This TTA-UC element was able to harvest red light transmitted through the active layer and chemically convert it (as described in detail below) to higher energy photons which could be absorbed by the active layer of the DSC and generate photocurrent. There are two important points to note about this system. Firstly, TTA-UC has many prospective advantages over other photon upconversion systems11; secondly it demonstrates a feasible architecture (proof-of-principle) for the incorporation of TTA-UC, which had been lacking from the TTA-UC literature up to that point.
The process of TTA-UC15-24 involves the excitation of &#8216;sensitizer&#8217; molecules, in this case Pd porphyrins, by light with energy below the device onset energy. The singlet-excited sensitizers undergo rapid intersystem crossing to the lowest-energy triplet state. From there, they can transfer energy to a ground-state triplet-accepting &#8216;emitter&#8217; species such as rubrene, as long as the transfer is allowed by free energy25. The first triplet state of rubrene (T1) is greater than half the energy of its first excited singlet state (S1) but less than half the energy of T2, meaning that an encounter complex of two triplet-excited rubrenes can annihilate to give one singlet excited emitter molecule (and the other in the ground state) with a fairly high probability. Other states, statistically predicted, are most likely energetically inaccessible for rubrene26. The singlet excited rubrene molecule can then emit a photon (as per fluorescence) with energy sufficient to excite the dye on the working electrode of the DSC. This process is shown in Animation 1.
TTA-UC offers a number of advantages compared to other UC systems, such as a broad absorption range and incoherent nature27, 28, making it an attractive option for coupling with DSC (as well as OPV). TTA-UC has been demonstrated operating at relatively low light intensities and in diffuse lighting conditions. Both DSC and OPV are most efficient in the low light intensity regime. Solar concentration is expensive and only justifiable for high efficiency, high cost devices. The relatively high performance of TTA-UC systems in low intensity lighting conditions is attributable to the process involving sensitizer chromophores with strong, broad absorption bands in concert with long-lived triplet states which are capable of diffusing in order to come into contact with interacting species. In addition, TTA-UC has been found to have high intrinsic efficiency from a kinetic study26.
Although TTA-UC operates at low light intensity, there is still a quadratic relationship between incident light intensity and emitted light (at least at low light intensities). This is due to the bimolecular nature of the process. To account for this and the varied experimental conditions (particularly light intensity) reported by different groups, a figure of merit (FoM) system should be employed to meter the performance enhancement offered by upconversion. This FoM has been defined as &#916;JSC/&#664;, where &#916;JSC is the increase in short circuit current (usually determined by integration of the Incident Photon to Charge Carrier Efficiency, IPCE, with and without the upconversion effect) and &#664; is the effective solar concentration (based on the photon flux in the relevant region, that is the Q-band absorption of the sensitizer)229.
Herein, a protocol for producing and correctly characterizing an integrated DSC-TTA-UC device is reported, paying special attention to potential pitfalls in device testing. It is hoped that this will serve as a basis for further work in this field.

<table border="0" cellpadding="0" cellspacing="0" width="1100">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Name of Material/ Equipment</td>
			<td style="width:200px;">Company</td>
			<td style="width:160px;">Catalog Number</td>
			<td style="width:245px;">Comments/Description</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:495px;">(tetrakis(3,5-di-tert-butylphenyl)-6&#8217;-amino-7&#8217;-nitro-tetrakisquinoxalino[2,3-b&#39;7,8-b&#39;&#39;12,13-b&#39;&#39;&#39;17,18-b&#39;&#39;&#39;&#39;-porphyrinato) palladium(II))</td>
			<td style="width:200px;">in house</td>
			<td style="width:160px;">in house</td>
			<td>Chem. Commun., 4851&#8211;4853 (2007)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1,2-dimethyl-3-propylimidazolium iodide</td>
			<td style="width:200px;">Solaronix</td>
			<td style="width:160px;">33150</td>
			<td>Material warning: Irritant</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">405 nm longpass filter</td>
			<td style="width:200px;">Semrock</td>
			<td>BLP01-405R-25</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">670 nm laser</td>
			<td style="width:200px;">Thorlabs</td>
			<td>LDS5 + CPS198</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Acetone</td>
			<td style="width:200px;">Chemsupply</td>
			<td style="width:160px;">AA008-20L-P</td>
			<td>Material warning: Flammable</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Acetonitrile</td>
			<td style="width:200px;">Sigma</td>
			<td style="width:160px;">271004</td>
			<td>Material warning: Flammable</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Alumina</td>
			<td style="width:200px;">Alfa Aesar</td>
			<td style="width:160px;">12733</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Alumina</td>
			<td style="width:200px;">Leeco</td>
			<td style="width:160px;">810-782</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Back filling chamber</td>
			<td style="width:200px;">Sistema</td>
			<td style="width:160px;">1303</td>
			<td>Kilip it round, modified</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Benzene</td>
			<td style="width:200px;">Scharlau</td>
			<td style="width:160px;">BE0033</td>
			<td>Material warning: Toxic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">BNC cable</td>
			<td style="width:200px;">Jaycar</td>
			<td style="width:160px;">RG- 59U</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Cerasolzer</td>
			<td style="width:200px;">MBR</td>
			<td style="width:160px;">CS186</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Chopper wheel</td>
			<td style="width:200px;">Thorlabs</td>
			<td>MC1000A</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Control software</td>
			<td style="width:200px;">in house</td>
			<td style="width:160px;">in house</td>
			<td>Written in LabVIEW</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Current Amplifier</td>
			<td>Standford Research&#160;</td>
			<td style="width:160px;">SR 570</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">D149 dye</td>
			<td style="width:200px;">1m</td>
			<td style="width:160px;">OSO149</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Dental burr</td>
			<td style="width:200px;">Priority dental supplies</td>
			<td style="width:160px;">835.104.008</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Detergent</td>
			<td style="width:200px;">Palmolive</td>
			<td style="width:160px;">Original</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Diamond wheel</td>
			<td style="width:200px;">Frameco</td>
			<td style="width:160px;">14220</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Drill</td>
			<td style="width:200px;">Dremmel</td>
			<td style="width:160px;">220</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Dynamic dignal acquisition device</td>
			<td>National Instruments</td>
			<td style="width:160px;">USB-4431</td>
			<td>Analog to Digital</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Ethanol</td>
			<td style="width:200px;">Univar</td>
			<td style="width:160px;">214</td>
			<td>Material warning: Flammable</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:495px;">F:SnO2 glass</td>
			<td style="width:200px;">Hartford</td>
			<td style="width:160px;">TEC8</td>
			<td>2.3mm, &#60; 8 &#937;/&#9633;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Glovebox</td>
			<td style="width:200px;">IT systems</td>
			<td style="width:160px;">-</td>
			<td>-</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:495px;">H2PtCl6</td>
			<td style="width:200px;">Sigma</td>
			<td style="width:160px;">334472</td>
			<td>Material warning: corrosive</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Hot melt adhesive gasket</td>
			<td style="width:200px;">Solaronix</td>
			<td style="width:160px;">Meltronic 1170-25</td>
			<td style="width:245px;">Surlyn</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Hot melt adhesive gasket</td>
			<td style="width:200px;">Solaronix</td>
			<td style="width:160px;">Meltronix 1170-60</td>
			<td style="width:245px;">Surlyn</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Hotplate</td>
			<td style="width:200px;">Harry Gestigkeit</td>
			<td style="width:160px;">PR 5 3T / PZ28-3T</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Hotplate</td>
			<td style="width:200px;">IKA</td>
			<td style="width:160px;">RCT basic</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Image analysis software</td>
			<td style="width:200px;">National Institutes for Health</td>
			<td style="width:160px;">Image-J</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Iodine</td>
			<td style="width:200px;">Sigma</td>
			<td style="width:160px;">326143</td>
			<td>Material warning: corrosive</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Laser engraver</td>
			<td style="width:200px;">Universal Laser Systems</td>
			<td style="width:160px;">PLS6WM</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Liquid Nitrogen</td>
			<td style="width:200px;">Air Liquide</td>
			<td style="width:160px;"></td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Lithium Iodide</td>
			<td style="width:200px;">Aldrich</td>
			<td style="width:160px;">518018</td>
			<td>Material warning: toxic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Methoxypropionitrile</td>
			<td style="width:200px;">Sigma</td>
			<td style="width:160px;">65290</td>
			<td>Material warning: Flammable</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Mirror</td>
			<td style="width:200px;">Thorlabs</td>
			<td style="width:160px;">PF10-03-P01</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Mirror mount</td>
			<td style="width:200px;">Thorlabs</td>
			<td style="width:160px;">KM100</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Monochromator</td>
			<td style="width:200px;">Spectral Products&#160;</td>
			<td>CM110</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Neutral density filters</td>
			<td style="width:200px;">Edmund Industrial Optics</td>
			<td style="width:160px;">64-352</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Parabolic mirror</td>
			<td style="width:200px;">Newport</td>
			<td style="width:160px;">50329AL, 50338AL</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Photodiode</td>
			<td>Newport</td>
			<td>918D-UV-OD3</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Power meter</td>
			<td>Newport</td>
			<td style="width:160px;">1936-C</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Rubrene</td>
			<td style="width:200px;">Sigma</td>
			<td style="width:160px;">551112</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Semi-automatic screen printer</td>
			<td style="width:200px;">Keywell</td>
			<td style="width:160px;">KY-500FH</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Spray pyrolyser</td>
			<td style="width:200px;">Glaskeller</td>
			<td style="width:160px;">-</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Tape</td>
			<td style="width:200px;">3M</td>
			<td style="width:160px;">Magic Tape</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Terminal block</td>
			<td style="width:200px;">Jaycar</td>
			<td>HM3194</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">tert-Butanol</td>
			<td style="width:200px;">Sigma</td>
			<td style="width:160px;">360538</td>
			<td>Material warning: Flammable</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">TiCl4</td>
			<td style="width:200px;">Sigma</td>
			<td style="width:160px;">89545</td>
			<td>Material warning: corrosive</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Tile</td>
			<td style="width:200px;">Johnson tiles</td>
			<td style="width:160px;">-</td>
			<td>-</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:495px;">Tile cutter</td>
			<td style="width:200px;">DTA</td>
			<td style="width:160px;">DTA-310</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">TiO2 paste</td>
			<td style="width:200px;">Dyesol</td>
			<td style="width:160px;">NR18-T</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Titanium diisopropoxide bis(acetylacetonate) (75% in isopropanol)</td>
			<td style="width:200px;">Aldrich</td>
			<td style="width:160px;">325252</td>
			<td>Material warning: Flammable</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Ultrasonic soldering iron</td>
			<td style="width:200px;">MBR</td>
			<td style="width:160px;">USS-9200</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">UV cure epoxy</td>
			<td style="width:200px;">Dymax</td>
			<td style="width:160px;">425</td>
			<td>Material warning: Irritant</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">UV cure system</td>
			<td style="width:200px;">Dymax</td>
			<td style="width:160px;">BlueWave 50</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">UV Visible Spectrophotometer</td>
			<td style="width:200px;">Varian Cary</td>
			<td style="width:160px;">1E</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Vacuum cuvette</td>
			<td style="width:200px;">Custom made</td>
			<td style="width:160px;">Custom made</td>
			<td>-</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:495px;">Vacuum pump</td>
			<td style="width:200px;">N/A</td>
			<td style="width:160px;">Rotary backed diffusion pump</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Wipes</td>
			<td style="width:200px;">Kimtech</td>
			<td style="width:160px;">34120KC</td>
			<td>Kimwipes</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:495px;">Xe lamp</td>
			<td>Energetiq&#160;</td>
			<td style="width:160px;">LDLSTM EQ-1500</td>
			<td style="width:245px;">White light source</td>
		</tr>
	</tbody>
</table>

integrating a triplet-triplet annihilation up-conversion system to enhance dye-sensitized solar cell response to sub-bandgap light

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.

Figures 3A - D display enhancement responses measured under different measurement conditions, with the effects discussed in more detail below. From the raw current density enhancements it should be clear that the results in Figure 4A and 4B are attributable to upconversion, with the peak current enhancement and IPCE enhancement matching well with the absorption spectrum of the sensitizer, attenuated by transmission through the active layer of the DSC.</p...

Watch this Scientific Journal Video about Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light at JoVE.com

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

An integrated device, incorporating a dye-sensitized solar cell and triplet-triplet annihilation up-conversion unit was produced, affording enhanced light harvesting, from a wider section of the solar spectrum. Under modest irradiation levels a significantly enhanced response to low energy photons was demonstrated, yielding a record figure of merit for dye-sensitized solar cells.

The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents ...

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