Optimering af Grätzel solceller: Grätzel Solar Cells

Louise Nielsen, Maria Hald, Pernille Petersen, Sofie K. Møhlenfeldt Hemmingsen & Stine Rosendal Tangaa

Studenteropgave: Semesterprojekt

Abstrakt

Abstrakt Udviklingen af effektive og stabile solceller er en mulig løsning på fremtidens energibehov. Prisen for traditionelle silicium solceller er for høj og derfor må billigere solceller udvikles. Vi arbejder med Grätzel solcellen, som er en fotoelektrokemisk solcelle(DSC), der er billig at fremstille og de bedste DSC celler kan omdanne ca. 10 % af solenergien til elektricitet. Desværre nedbrydes ruthenium-farvestoffet RuL2(NCS)2 i Grätzel solcellen ved 85 °C i løbet af kun 120 timer ved reaktion med solcelle additivet 4-tertiær-butylpyridin(4-TBP). Vi har vist, at simpel sterisk hindring kan besværliggøre denne reaktion. I projektet udskiftes pyridin-additivet 4-TBP med henholdsvis 2-piccoline, 3-piccoline, 4-piccoline og 2,6-lutedin. Vi målte halveringstiden(T½) for reaktionen mellem RuL2(NCS)2 og de udvalgte pyridiner, samt nyttevirkning(η). Ved 100 °C lå T½ for 4-TBP(69 timer) meget lavere end 2,6 lutedin(254 timer) og 3-piccoline(139 timer). η for 4-TBP(0,35 %) lå meget lavere end de resterende pyridiner. 2,6-lutedin(1,08 %) og 3-piccoline(1,03 %) var mere end dobbelt så effektive. Vores solceller havde generelt en dårlig η, men der må tages højde for at vi kun konstruerede solcellerne en gang. Projektet påviser, at indbyggelse af sterisk hindring i additiv molkylerne vil reducere hastigheden af reaktionen mellem RuL2(NCS)2 og pyridin additivet i Grätzel solcellen, og hermed forlænge solcellens levetid ved høj temperatur. Abstract The development of efficient and stable solar cells is a possible solution to future energy needs. Traditional silicon solar cells are too expensive and therefore more affordable solar cells have to be developed. We work with Grätzel solar cells as a Dye Sensitized solar Cell (DSC), which is cheap to produce. The best can transform about 10% of the solar energy into electricity. Unfortunately the dye RuL2 (NCS)2 in Grätzel solar cells decomposes at 85°C in only 120 hours by reacting with 4-tertiary-butylpyridin(4-TBP). We have shown that simple steric hindrance can hamper this reaction. We have changed the pyridine additive 4-TBP with 2-piccoline, 3-piccoline, 4-piccoline and 2,6-lutedin. We measured the half-life (T½) for the reaction between RuL2 (NCS)2 and the pyridines, along with the efficiency (η). At 100°C the T½ for 4-TBP (69 hours), was much lower than for 2,6 lutedin (254 hours) and 3-piccoline(139 hours). 4-TBP´s η (0.35 %) was lower than for the remaining pyridines. 2.6-lutedin (1.08%) and 3-piccoline (1.03 %) was more than twice as effective. Generally our solar cells had a low η, but one must take into consideration that we only tried to design the solar cells once. The project demonstrates that steric hindrance will have a positive impact on the reaction between the dye and the pyridine in Grätzel solar cells.

UddannelserBasis - Naturvidenskabelig Bacheloruddannelse, (Bachelor uddannelse) Basis
SprogDansk
Udgivelsesdato27 maj 2009
VejledereTorben Lund

Emneord

  • Solar cells
  • Grätzel