Room-Temperature-Processed, Carbon-Based Fully Printed Mesoscopic Perovskite Solar Cells with 15% Efficiency

Methylamine (MA) and methylamine hydrochloride (MACl) are widely used to prepare highly efficient and stable perovskite solar cells (PSCs). However, MA, as a gas, is difficult to handle and inevitably leads to a large amount of escape, and it is difficult to quantitatively calculate. Herein, selecting a mixture solvent of methylamine ethanol solution (MA-EtOH sol) and acetonitrile (ACN) as a solvent, a new strategy for preparing fully printed mesoscopic perovskite solar cells (MPSCs) at room temperature is first proposed. With the introduction of 20 mol% MACl as additive, the fully printed MPSCs are fabricated without any posttreatment at room temperature via a one-step drop-coating method. As a consequence, the average power conversion efficiency (PCE) of 14.73 +/- 0.3% (0.1 cm(2)) with almost no hysteresis is achieved. Most importantly, the device also exhibits excellent long-term stability when it is unencapsulated. Specifically, the unencapsulated device still retains nearly 100% of its original PCE after 64 days and 88% after 81 days of storage in the dark with a humidity of 50 +/- 5% in an atmospheric environment. It provides a new idea for constructing fully printed MPSCs at room temperature in the future.

Automated summary

This study successfully prepared highly efficient and stable fully printed mesoscopic perovskite solar cells at room temperature using a mixture solvent and additive method. The devices showed excellent long-term stability in unencapsulated conditions, providing a new idea for constructing fully printed mesoscopic perovskite solar cells at room temperature in the future.