Effect of carbon quantum dots and Zn2+ ion on perovskite solar cells

Perovskite solar cells (PSCs) have a great attention due to their remarkable performance and a high-quality perovskite film is necessary to achieve high power conversion efficiency (PCE). The effect of carbon quantum dots (CQDs) and Zn2+ ions on perovskite layer of methyl ammonium lead iodide (MAPbI3) was investigated. The optical, structural, and morphological properties of perovskite films with different Zn2+ ratios and CQDs contents were investigated. It was observed that 1% ZnCl2 /0.05 mg/mL CQDs perovskite film composed of uniform grains distribution, complete surface coverage with negligible pinholes, and a larger grain size of 1.8 μm. In addition, it was found that increasing CQDs contents to 0.1 and 0.25 mg/mL enlarged the grain size to ~ 4.2 μm. Moreover, the incorporation of CQDs enhanced crystallinity and grain size. Consequently, these improvements were reflected on the solar cell performance and the efficiency of PSCs with additive of 1% ZnCl2-0.05 mg/mL CQDs was improved from 4.21 to 8.08%.