| 초록 |
For practical use of perovskite solar cells (PSCs) the instability issues of devices, attributed to degradation of perovskite molecules by moisture, ions migration, and thermal- and light-instability, have to be solved. To solve such issues, we developed simple methods for production of metal oxide and graphene based functional composites such as Ag-rGO, perovskite-NiO, perovskite/Ag-rGO, NiO-carbon-graphite and Al2O3/graphene, and utilized them for PSCs. We reported highly efficient and stable PSCs based on perovskite/Ag-reduced graphene oxide (Ag-rGO) and mesoporous Al2O3/graphene (mp-AG) composites. The mp-AG composite was conductive with one-order of magnitude higher mobility than mp-TiO2 and used for electron transport layer (ETL). Compared to the mp-TiO2 ETL based cells, the champion device based on perovskite/Ag-rGO and SrTiO3/mp-AG composites showed overall a best performance. More importantly, the champion device without encapsulation exhibited not only remarkable thermal- and photo-stability but also long-term stability with retaining 97-99 % of the initial values of photovoltaic parameters with sustaining ~ 93% of initial PCE over 300 days under ambient conditions. |
