Dye-sensitized Solar Cell Structure
Suitable for High Power Module
Ichiro Gonda*, Yasuo Okuyama*, Junya Takashima*
and Keizo Furusaki*, Satoshi Uchida***R&D Center NGK SPARK PLUG CO., LTD
2808 Iwasaki, Komaki, Aichi, 485-8510, Japan**IMRAM, Tohoku Univ.
1-1, Katahira 2-chome, Aoba-ku, Sendai, 980-8577, Japan

Result and Discussion
The cell worked quite efficiently as much as DSSC
module is expected. Details will be presented at theconference.
Dye-sensitizednanocrystalline TiO2 layer
Conducting glass

Introduction
Dye-sensitized solar cell (DSSC) draw a quite attention
to meet future solar energy market demanding low costphotovoltaic devices, because the manufacturing process isrelatively simple.

Polymer
Pt catalyst
sealantFig. 1 Cross section of a conventional dye-sensitizedsolar cell
Electrolyte

Since a single cell of DSSC generates only the low
voltage not more than 0.7V, and it is necessary to make anin-series connection of cells to obtain much higher voltage
for practical application. The problem here is that theconventional structure of DSSC comprises two substrates
that have one electrode on each (Fig. 1), and to make anin-series connection of cells; the connecting structure
would be complicated as much as fabrication process ofthe high power DSSC module, and may loose advantageof the simple manufacturing process mentioned earlier.
To maintain the simple DSSC module structure, wehave developed the monolithic structure by adapting thefine lithography of our microprocessor technology on
ceramic substrates as the same technique as our ceramic
microprocessor packages.
As shown in Fig. 2, the newly designed cell is formed
on a single plane of a ceramic substrate and screen printed
a pair of interdigitated tungsten electrodes; which haveexcellent tolerance against I3-/I- electrolyte, with line andspace less than 100 micrometers.

Electrolyte
Glass(no conducting)Dye-sensitizednanocrystalline TiO2 layers
on an interdigitated electrode

Substrate
Pt catalytic layers
on an interdigitated electrode

Polymersealant

Fig. 2 Cross section of the newly designed cell structure

larger number of series
for higher voltage

Followings are advantages of this configuration.
-Simpler DSSC module fabrication by simultaneous
formation of pair electrodes on a substrate.
-The electrical resistance of fine printed interdigitatedelectrodes is pretty low enough for a large scale DSSC.
-As shown in Fig. 3, the newly designed structure caneasily obtain the voltage that required by in-seriesconnection, and can also obtain larger current bylengthening the arrays of interdigitated electrodes.
-By forming another dye-sensitized TiO2 layer on
conducting glass as third electrode, a tandem structure ina single compartment can be easily realized; which
contributes further more efficient light harvesting.

longer array for larger current
Fig. 3 Module substrate for the newly designed cellstructure

Glass (no conducting)Experimental
In Fig. 4, a typical cell structure is explained.
1. A pair of tungsten interdigitated electrodes of 50-100
micrometers width and 50-100 micrometers gap werescreen-printed on an Al2O3 substrate and co-fired.
2. Pt catalytic layers of 200 nanometers were formed on
one of the electrodes.
3. On the other electrode, TiO2 layers, which average
particle diameter is about 20 nanometers, were formed,
and immersed into dye solution for 24 hours.
4. Polymer sealant gel was screen-printed on the edge ofthe substrate, and was solidified by heat-treatment after
glass was stuck onto the substrate.
5. Liquid electrolyte is impregnated through small holeson the substrate, and sealed by polymer sealant.

Polymer sealantDye-sensitizednanocrystalline TiO2
Pt catalytic layers
A pair of interdigitated tungsten
electrodes on a single plane of aceramic substrate
Fig. 4 Example of the newly designed cell structure