Nanostructured 2D perovskites for high efficiency photovoltaics
Lee, Zhi Yi
Date of Issue2016-05-14
School of Materials Science and Engineering
Energy Research Institute @ NTU (ERI@N)
Solar cells are one of the common renewable energies that have been used worldwide. Having this renewable energy resources installed at your home would save the cost of electricity bills. In the recent years, third generation perovskite solar cells have evolved rapidly. With its low material cost and production, it can yield an efficiency of up to 22.1% which is as good as single crystalline silicon solar cells sold in the market. However, the well-studied three-dimensional hybrid perovskite absorbers have low moisture stability thus researchers have employed two-dimensional hybrid perovskites absorber to counter the moisture instability. In conventional 2D perovskite solar cells, they suffer from low device performances due to the charge transport between the inorganic lattices which are separated by the larger organic cations. Here, (IEA)2(MA)n-1PbnI3n+1 [IEA = IC2H4NH3+ ; MA = CH3NH3+] (n = 1, 2, 3, 4 and 5) was being experimentally done via two different types of deposition methods: single step and sequential which yields planar and nanostructured microstructures respectively. These outstanding (IEA)2(MA)n-1PbnI3n+1 compounds exhibit a halogen-halogen and hydrogen-hydrogen bonding between two inorganic interface at which it reduces the bandgap as well as enhances the moisture stability. This study sought to characterise the lower dimensional perovskites fabricated from single step and sequential deposition through photophysical and morphological characterisation and their photovoltaic applications. Further studies can be done to improve its solar cell efficiency by surface passivation of the nanostructured perovskite in order to minimize the interfacial recombination and implementing mixed-cation approach for achieving more stable and highly efficient solar cells.
Final Year Project (FYP)
Nanyang Technological University