미래를 창조하는 포스텍 화학공학과
Enhanced Efficiency and Stability of an Aqueous Lead-Nitrate-Based Org…
- Year of publication
- Title of paper
- Enhanced Efficiency and Stability of an Aqueous Lead-Nitrate-Based Organometallic Perovskite Solar Cell
- [박태호교수 연구실]
- Publication in journal
ACS Applied Matererial and Interfaces 9, pp14023-14030.
- Publication date
We investigate the stability of an active organometallic perovskite layer prepared from a two-step solution procedure, including spin coating of aqueous lead nitrate (Pb(NO3)2) as a Pb2+ source and
sequential dipping into a methylammonium iodide (CH3NH3I) solution. The conversion of CH3NH3PbI3 from a uniform Pb(NO3)2 layer generates PbI2-free and large-grain perovskite crystallites owing to an intermediate ionexchange reaction step, resulting in improved humidity resistance and, thereby, improved long-term stability with 93% of the initial power conversion efficiency (PCE) after a period of 20 days. The conventional fast-converted PbI2-dimethylformamide solution system leaves small amounts of intrinsic PbI2 residue on the resulting perovskite and MAPbI3 crystallites with uncontrollable sizes. This accelerates the generation of PbI2 and the decomposition of the perovskite layer, resulting in poor stability with less than 60% of the initial PCE after a period of 20 days.