Perovskite solar cells (PSCs) have attracted much attention due to their impressive photovoltaic performance and low fabrication cost. The perovskite layer plays a critical role in light-to-electricity conversion. Here we study the effects of alkali metal ion dopants on the growth, structure and properties of perovskite films and the photovoltaic performance of PSCs. At a low doping level, the alkali metal ions can significantly affect the formation and properties of the perovskite films. They can enhance the short-circuit current density (Jsc) and power conversion efficiency (PCE) significantly. The Jsc increases significantly from 19.2 mA cm-2 to 21.0 mA cm-2 and 20.3 mA cm-2 for the PSCs with a methylammonium lead triode layer doped with 0.5 mol% K+ and 0.25 mol% Na+, respectively, and the fill factor (FF) increases from 0.74 to 0.79 for the devices with both doping ions. Correspondingly, the PCE increases from 13.7% to 15.3% and 14.6% for the PSCs, respectively. The efficiency improvement by K+ or Na+ doping is attributed to their effect in increasing the crystallinity and crystallite size of the perovskite films.
ASJC Scopus subject areas
- General Chemistry
- Renewable Energy, Sustainability and the Environment
- General Materials Science