Solar Energy has many challenges and disadvantages preventing its widespread use and implementation. Current silicon solar panel technology is still more expensive than coal and oil. The need for alternative energy sources has driven research for high efficiency and low-cost solar cells. The previous electron transport material (ETL) is TiO₂, which needs high processing temperature (~400°C), which limits many applications using flexible substrates. Tin oxide layer can be processed at low temperatures (<200°C). It is promising for applications for flexible substrates.

My research is focused on perovskite solar cells utilizing tin oxide nanoparticle as ETL. Tin oxide layer was spin coated and annealed in order to create a conductive electron transport material. In this study, we will compare two precursor materials: SnCl₄ nanoparticles in ethanol solution and SnO₂ nanoparticles in aqueous solution. We found that the ETL using SnCl₄ nanoparticles results in much poorer performance of solar cells with a power conversion efficiency (PCE) of 12.32% (Figure 1) and the ETL using SnO₂ nanoparticles results in much better solar cells with PCE of approximately 18.13% (Figure 2). Therefore, SnO₂ nanoparticle is a promising ETL material for high efficiency perovskite solar cells.

a)b)

Figure 1: a) I-V curves of a solar cell with SnO₂ ETL using SnCl₄ precursor. Poor performance (12% PCE) and large hysteresis observed. b) I-V curves of a solar cell with SnO₂ ELT using SnO₂ nanoparticle precursor. Lower hysteresis and higher PCE (18%) observed.