Efficient monolithic all-perovskite tandem solar modules with small cell-to-module derate

Efficient and stable formamidinium–caesium perovskite solar cells and modules from lead acetate-based precursors

“…Although, it was reported that the use of nitrogen blades can help produce high quality perovskite thin films from slot-die coating or blade coating without the use of an antisolvent, 24,25 the addition of strongly coordinating solvents such as DMSO or NMP is widely carried out to form perovskite-solvent intermediates and control the perovskite crystallization. [26][27][28][29] The addition of these solvents has been found to be detrimental to the device stability as they can easily be trapped in the films and lead to the formation of voids at the perovskite substrate interface due to their high boiling points and strong coordination ability. [30][31][32][33][34] Although, there is still an ongoing debate in the literature on the impact of these voids with a recent study suggesting that they are not necessarily detrimental to the device stability.…”

Suppressing Nonradiative Losses in Wide-Band-Gap Perovskites Affords Efficient and Printable All-Perovskite Tandem Solar Cells with a Metal-Free Charge Recombination Layer

“…In addition, the I/Br ratio of 7/3 gives a band gap of 1.71 eV, which is of particular interest as the front absorber for tandem devices. It is worth noting that, in contrast to previous reports where the wide-band-gap perovskites were prepared by spin-coating, − all of the perovskite thin films in the present work were fabricated by scalable blade-coating, which was recently developed in our laboratories as a reliable protocol for producing high-quality perovskite thin films. − Vacuum-assisted solvent quenching, which was developed in our laboratories to great maturity, is used to achieve reproducible crystallization of the perovskite films by decoupling the freshly coated wet precursor film from the subsequent thermal annealing (Figure a). Analogous to the deposition of pristine films, we prepare bulk- and interface-passivated perovskite thin films by introducing a small amount of MASCN into the precursor and successively depositing a solution of phenethylammonium iodide (PEAI) on MASCN-based films, respectively.…”

“…For monolithic tandem devices, in addition to the preparation of efficient individual perovskite subcells, the charge recombination layer plays an essential role in determining the photovoltaic performance, which should concurrently possess low contact resistance, high optical transparency, and mechanical robustness. Early works mainly used sputtered ITO as both the electron transport layer and solvent resistance layer. ,,− However, sputtered ITO not only induces parasitic absorption but also poses a threat to destroy the underlying wide-band-gap perovskite due to damage from high-energy electrons generated during sputtering.…”

“…It is also noticed that both fill factors (FFs) of up to 80% and external quantum efficiencies (EQEs) approaching 90% have been achieved in all-perovskite tandem devices, , manifesting that electrons and holes generated in the adjacent two subcells can recombine efficiently at recombination layers without losses. However, almost all state-of-the-art all-perovskite tandem devices incorporate a thin metal (Ag or Au) film between the recombination layers of “atomic layer deposited SnO 2 (ALD-SnO 2 )/poly­(3,4-ethylenedioxythiophene)-poly­(styrenesulfonate) (PEDOT:PSS)” to realize an Ohmic contact. ,− It is apparent that the insertion of this thin metal film not only complicates device fabrication but also induces undesired optical losses due to the plasmonic absorption.…”

Surface Sn(IV) Hydrolysis Improves Inorganic Sn–Pb Perovskite Solar Cells

“…32,33 SnO x is a typical electron transport material, 34 and its in situ generation on the perovskite surface can facilitate the electron extraction on the device ETL side. 33 Moreover, further H 2 O treatment of the film surface decreases the carrier lifetime to 5.78 ns (Figure 2g), which is attributed to the fluorescence quenching caused by the improvement of the electron extraction from perovskite to SnO x . On a closer examination, we found that the H 2 O treatment can promote the formation of a low-dimension (LD) perovskite.…”