Crystal-facet-directed all vacuum-deposited perovskite solar cells
Nature Materials Springer Nature
Authors:
Xinyi Shen, Wing Tung Hui, Shuaifeng Hu, Fengning Yang, Junke Wang, Jin Yao, Atse Louwen, Bryan Siu Ting Tam, Lirong Rong, David McMeekin, Kilian Lohmann, Qimu Yuan, Matthew Naylor, Manuel Kober-Czerny, Seongrok Seo, Philippe Holzhey, Karl-Augustin Zaininger, Mark Christoforo, Perrine Carroy, Vincent Barth, Fion Sze Yan Yeung, Nakita Noel, Michael Johnston, Yen-Hung Lin, Henry Snaith
Abstract:
Vacuum-based deposition is a scalable, solvent-free industrial method ideal for uniform coatings on complex substrates. However, all vacuum-deposited perovskite solar cells fabricated by thermal evaporation trail solution-processed counterparts in efficiency and stability due to film quality challenges, necessitating advancement and improved understanding. Here, we report a co-evaporation route for 1.67-eV wide-bandgap perovskites by introducing a PbCl2 co-source to optimize film quality. We promote perovskite formation with pronounced (100) “face-up” orientation and deliver a certified all vacuum-deposited solar cell with 18.35% efficiency (19.3% in the lab) for 0.25-cm2 devices (18.5% for 1-cm2 cells). These cells retain 80% of peak efficiency after 1,080 hours under the ISOS-L-2 protocol. Leveraging operando hyperspectral imaging, we provide spatiotemporal spectral insight into halide segregation and trap-mediated recombination, correlating microscopic luminescence features with macroscopic device performance while distinguishing radiative from non-ideal recombination channels. We further demonstrate 27.2%-efficient 1-cm2 evaporated perovskite-on-silicon tandems and outdoor stability of all vacuum-deposited tandems in Italy, retaining ~80% initial performance after 8 months.
