The 77th JSAP Autumn Meeting, 2016

Presentation information

Poster presentation

13 Semiconductors » 13.10 Compound solar cells

[14p-P21-1~27] 13.10 Compound solar cells

Wed. Sep 14, 2016 4:00 PM - 6:00 PM P21 (Exhibition Hall)

4:00 PM - 6:00 PM

[14p-P21-23] Sulfurization of Cu-In particles in Aqueous Solution

〇(M2)Hugo Erawan1, Shun Yokoyama1, Hideyuki Takahashi1, Kazuyuki Tohji1 (1.Tohoku Univ.)

Keywords:Copper indium particles, sulfurization, CIS solar cells

Copper Indium Gallium Selenide (CIGS) solar cells are very advantageous solar cells. CIGS solar cells can achieve high efficiency, uses a small amount of material (thin film), and can be deposited on flexible substrates. Co-evaporation as the main manufacturing process for high efficiency devices has some disadvantages such as being difficult to control, requiring high temperature and wasting materials,
Non-vacuum particulate based process is a possible simpler and cheaper alternative to co-evaporation where particles can be directly deposited on to a substrate by methods such as printing. In our laboratory, copper indium (Cu-In) nanoparticles have been synthesized as precursor for printing solar cells. However, up to this point, selenization by using highly toxic hydrogen selenide gas at temperature high temperature was necessary to obtain copper indium selenide phase.
In this experiment, we try to replace the toxic gas selenization process by a process in aqueous solution. Because selenium is highly toxic material, we focus on sulfurization first instead of selenization. The goal is to obtain copper indium sulfide phase
Synthesized Cu-In NPs was sulfurized by mixing in aqueous solution with sulfur ions. Sodium sulfide was used as sulfur ion source.
Our results shows that sulfurization with 0.5 M Na2S solution at 50oC showed some phase change into possibly copper sulfide. At 5 hours reaction time indium concentration in the particles was very low, possibly because it had formed indium sulfide which was subsequently dissolved in the solution. To prevent indium leaking out, sodium sulfide solution saturated with indium sulfide was used for sulfurization. Higher indium concentration was retained in the particles, however, no copper indium sulfide phase has been observed.