Binary solvent system used to fabricate fully annealing-free perovskite solar cells

Journal article

High temperature post-deposition annealing of hybrid lead halide perovskite thin films—typically lasting at least 10 min—dramatically limits the maximum roll-to-roll coating speed, which determines solar module manufacturing costs. While several approaches for “annealing-free” perovskite solar cells (PSCs) have been demonstrated, many are of limited feasibility for scalable fabrication. Here, this work has solvent-engineered a high vapor pressure solvent mixture of 2-methoxy ethanol and tetrahydrofuran to deposit highly crystalline perovskite thin-films at room temperature using gas-quenching to remove the volatile solvents. Using this approach, this work demonstrates p-i-n devices with an annealing-free MAPbI₃ perovskite layer achieving stabilized power conversion efficiencies (PCEs) of up to 18.0%, compared to 18.4% for devices containing an annealed perovskite layer. This work then explores the deposition of self-assembled molecules as the hole-transporting layer without annealing. This work finally combines the methods to create fully annealing-free devices having stabilized PCEs of up to 17.1%. This represents the state-of-the-art for annealing-free fabrication of PSCs with a process fully compatible with roll-to-roll manufacture.

Authors: Cassella, EJ; Spooner, ELK; Smith, JA; Thornber, T; O'Kane, ME

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Advanced Energy Materials
• Volume: 13
• Issue: 11
• Article number: 2203468
• Publication date: 2023-02-09
• DOI: 10.1002/aenm.202203468
• EISSN: 1614-6840
• ISSN: 1614-6832
• Language: English
• Keywords: annealing free; perovskite solar cells; FFR; solar energy; self-assembled monolayers