Tin-Based Perovskite Solar Cells Reach Over 13 with Inclusion of N-Doped Graphene Oxide in Active, Hole-Transport, and Interfacial Layers

摘要

Tin-based perovskite (Sn-PS) is one of the most promising candidatesin lead-free perovskite solar cells (PSCs), but its poor stability andlow power conversion efficiency (PCE) have been the main bottlenecktowards further development. Here, to develop a stable and efficientSn-based PSC, nitrogen-doped graphene oxide (N_xGO) has been, for thefirst time, incorporated in active, hole-transport and interfacial layers.The inclusion of N_xGO slowed the crystallization of Sn-PS and suppressedthe Sn~(2+)/Sn~(4+) oxidation, resulting in pinhole-free dense filmshaving large grains, reduction of recombination loss, well-matchedenergy levels, and thereby significantly improving the device performance.Compared to the pristine Sn-PS cells, the champion deviceswith N_xGO-based composites in active, hole-transport, and interfaciallayers showed dramatic enhancement of photovoltaic parameters(i.e., open-circuit voltage = 0.961 V, photocurrent = 21.21 mA cm~(?2),fill factor = 65.05% and PCE = 13.26%). Furthermore, the N_xGO-basedcells without encapsulation showed remarkable improvement oflong-term stability with sustaining 91% of the initial PCE over 60 d,photostability, and reproducibility.