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Method Article

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

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DOI:

10.3791/52028

September 12th, 2014

In This Article

Summary

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.

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.

Introduction

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 DS....

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Protocol

1. DSC Fabrication

1.1. Working Electrode Preparation

  1. Clean one whole sheet of F:SnO2 coated glass (110 mm × 110 mm × 2.3 mm, <8 Ω/□) by sonication sequentially in soapy water, then acetone and finally ethanol (10 min each).
  2. Deposit a dense layer of TiO2 following the steps below:
    1. Dry glass using compressed air and heat glass to 450 °C on hotplate (conductive side up).
    2. Dilute Titanium diisopropoxide bis(acetylacetonate) (75 wt% in isopropanol) with ethanol in a 1:9 ratio.
    3. Spray the dilute solution onto heated glass from a distance of ~10....

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Results

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.

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Discussion

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 ΔJSC 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.......

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Disclosures

There is nothing to disclose.

Acknowledgements

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’s Discovery Projects funding scheme (DP110103300). Equipment was purchased with support from the Australian Research Council (LE0668257).

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Materials

List of materials used in this article
NameCompanyCatalog NumberComments
(tetrakis(3,5-di-tert-butylphenyl)-6’-amino-7’-nitro-tetrakisquinoxalino[2,3-b'7,8-b''12,13-b'''17,18-b''''-porphyrinato) palladium(II))in housein houseChem. Commun., 4851–4853 (2007)
1,2-dimethyl-3-propylimidazolium iodideSolaronix33150Material warning: Irritant
405 nm longpass filterSemrockBLP01-405R-25-
670 nm laserThorlabsLDS5 + CPS198-
AcetoneChemsupplyAA008-20L-PMaterial warning: Flammable
AcetonitrileSigma271004Material warning: Flammable
AluminaAlfa Aesar12733
AluminaLeeco810-782
Back filling chamberSistema1303Klip it round, modified
BenzeneScharlauBE0033Material warning: Toxic
BNC cableJaycarRG- 59U
CerasolzerMBRCS186
Chopper wheelThorlabsMC1000A
Control softwarein housein houseWritten in LabVIEW
Current AmplifierStandford Research SR 570
D149 dye1mOSO149
Dental burrPriority dental supplies835.104.008
DetergentPalmoliveOriginal
Diamond wheelFrameco14220
DrillDremmel220
Dynamic dignal acquisition deviceNational InstrumentsUSB-4431Analog to Digital
EthanolUnivar214Material warning: Flammable
GloveboxIT systems
H2PtCl6Sigma334472Material warning: corrosive
Hot melt adhesive gasketSolaronixMeltronic 1170-25Surlyn
Hot melt adhesive gasketSolaronixMeltronix 1170-60Surlyn
HotplateHarry GestigkeitPR 5 3T / PZ28-3T
HotplateIKARCT basic
Image analysis softwareNational Institutes for HealthImage-J
IodineSigma326143Material warning: corrosive
Laser engraverUniversal Laser SystemsPLS6WM
Liquid NitrogenAir Liquide
Lithium IodideAldrich518018Material warning: toxic
MethoxypropionitrileSigma65290Material warning: Flammable
MirrorThorlabsPF10-03-P01
Mirror mountThorlabsKM100
MonochromatorSpectral Products CM110
Neutral density filtersEdmund Industrial Optics64-352
Parabolic mirrorNewport50329AL, 50338AL
PhotodiodeNewport918D-UV-OD3
Power meterNewport1936-C
RubreneSigma551112
Semi-automatic screen printerKeywellKY-500FH
Spray pyrolyserGlaskeller
Tape3MMagic Tape
Terminal blockJaycarHM3194
tert-ButanolSigma360538Material warning: Flammable
TiCl4Sigma89545Material warning: corrosive
TileJohnson tiles
Tile cutterDTADTA-310
TiO2 pasteDyesolNR18-T-
Titanium diisopropoxide bis(acetylacetonate) (75% in isopropanol)Aldrich325252Material warning: Flammable
Ultrasonic soldering ironMBRUSS-9200
UV cure epoxyDymax425Material warning: Irritant
UV cure systemDymaxBlueWave 50
UV Visible SpectrophotometerVarian Cary1E
Vacuum cuvetteCustom madeCustom made
Vacuum pumpRotary backed diffusion pump
WipesKimtech34120KCKimwipes
Xe lampEnergetiq LDLSTM EQ-1500White light source

References

  1. O'Regan, B., Grätzel, M. A low-cost, high-efficiency solar-cell based on dye-sensitized colloidal TiO2 films. Nature. 353, 737-740 (1991).
  2. Grätzel, M. Photoelectrochemical cells. Nature. 414 (6861), 338-344 (2001).
  3. Hagfeldt, A., Boschloo, G., Sun, L., Kloo, L., Pettersson, H.

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Tags

Dye sensitized Solar CellsSub bandgap Light ResponsePalladium Porphyrin SensitizerRubrene EmitterOrganic Dye D149Double Chamber AssemblyIncident Photon Current EfficiencyPump Beam TechniqueElectrical Contact Formation