Electrical properties of dye-sensitized solar module with integrated parallel connections

Despite the rapid development of dye-sensitized solar cell since its early breakthrough by Graetzel in 1991, further development on the design and fabrication technique still constitutes a major challenge for this type of solar cell to reach the mass production and marketing level. Generally, the upscaling of dye-sensitized solar cell for daily utilizations necessitates the interconnection of multiple cells to form modules. In this regard, the use of screen-printing method could provide a major benefit to fabricate such structure as it is feasible for industrial and large scale manufacturing process. This contribution describes the fabrication of a 100 × 100 mm2 dyesensitized solar module using semi-automatic screen-printing technique. The fabricated modules comprised of 7 individual cells made from titanium dioxide (TiO2) nanocrystalline films, each with an active area size of 10 × 70 mm2, giving an active area ratio of 70%. The cells were connected to the neighboring cells in a parallel configuration. To simulate the potential of the fabricated modules for indoor applications, the current-voltage characteristics of the module were measured under an ambient lighting with an intensity of 30 mW/cm2. The parallel interconnected dye-sensitized solar module produced an open circuit voltage (VOC) of 0.71 V with a short circuit current (ISC) of 21.73 mA and maximum power output (Pmax) of 4.19 mW. Overall, the fabricated module achieved a power conversion efficiency of 1.99%. A secondary measurement under simulated sun with an intensity of 50 mW/cm2 (0.5 Sun) was also carried out to compare the performance of the modules under different environment. Under the later condition, the VOC, ISC, Pmax, and efficiency obtained were 0.77 V, 27.64 mA, 5.47 mW, and 0.15%, respectively. Our results indicated that the dye-sensitized solar module with integrated parallel connection has a prominent advantage to be applied as an energy source for applications that requires high current input under low-light condition.