| Affiliation: | 1. Guangdong Provincial Key Laboratory of Durability for Ocean Civil Engineering, College of Civil and Transportation Engineering, Shenzhen University, Shenzhen, 518060 P. R. China
Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060 P. R. China;2. Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060 P. R. China;3. Laboratory of Photonics and Interfaces (LPI), Department of Chemistry and Chemical Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015 Switzerland;4. Guangdong Provincial Key Laboratory of Durability for Ocean Civil Engineering, College of Civil and Transportation Engineering, Shenzhen University, Shenzhen, 518060 P. R. China |
| Abstract: | Surface defects cause non-radiative charge recombination and reduce the photovoltaic performance of perovskite solar cells (PSCs), thus effective passivation of defects has become a crucial method for achieving efficient and stable devices. Organic ammonium halides have been widely used for perovskite surface passivation, due to their simple preparation, lattice matching with perovskite, and high defects passivation ability. Herein, a surface passivator 2,4,6-trimethylbenzenaminium iodide (TMBAI) is employed as the interfacial layer between the spiro-OMeTAD and perovskite layer to modify the surface defect states. It is found that TMBAI treatment suppresses the nonradiative charge carrier recombination, resulting in a 60 mV increase of the open-circuit voltage (Voc) (from 1.11 to 1.17 V) and raises the fill factor from 76.3% to 80.3%. As a result, the TMBAI-based PSCs device demonstrates a power conversion efficiency (PCE) of 23.7%. Remarkably, PSCs with an aperture area of 1 square centimeter produce a PCE of 21.7% under standard AM1.5 G sunlight. The unencapsulated TMBAI-modified device retains 92.6% and 90.1% of the initial values after 1000 and 550 h under ambient conditions (humidity 55%–65%) and one-sun continuous illumination, respectively. |
