Deterministic fabrication of 3D/2D perovskite bilayer stacks for durable and efficient solar cells

• DOI: 10.1126/science.abq7652
• Publication Date: 2022-09-22T17:57:32Z
• Authors: Siraj Sidhik; Yafei Wang; Michael De Siena; Reza Asadpour; Andrew J. Torma; Tanguy Terlier; Kevin Ho; Wenbin Li; Anand B. Puthirath; Xinting Shuai; Ayush Agrawal; Boubacar Traore; Matthew Jones; Rajiv Giridharagopal; Pulickel M. Ajayan; Joseph Strzalka; David S. Ginger; Claudine Katan; Muhammad Ashraful...; Jacky Even; Mercouri G. Kanat...; Aditya D. Mohite
• Keywords: [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry; [CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry; 7. Clean energy; 01 natural sciences; 0104 chemical sciences

Realizing solution-processed heterostructures is a long-enduring challenge in halide perovskites because of solvent incompatibilities that disrupt the underlying layer. By leveraging the solvent dielectric constant and Gutmann donor number, we could grow phase-pure two-dimensional (2D) halide perovskite stacks of the desired composition, thickness, and bandgap onto 3D perovskites without dissolving the underlying substrate. Characterization reveals a 3D–2D transition region of 20 nanometers mainly determined by the roughness of the bottom 3D layer. Thickness dependence of the 2D perovskite layer reveals the anticipated trends for n-i-p and p-i-n architectures, which is consistent with band alignment and carrier transport limits for 2D perovskites. We measured a photovoltaic efficiency of 24.5%, with exceptional stability ofT99(time required to preserve 99% of initial photovoltaic efficiency) of >2000 hours, implying that the 3D/2D bilayer inherits the intrinsic durability of 2D perovskite without compromising efficiency.