Passivation of perovskite surfaces using 2-hydroxyacetophenone to fabricate solar cells with over 20.7% efficiency under air environment

Surface pre-sacrifice behavior of thiourea-based 2D perovskites for high-performance perovskite solar cells

“…4b. The defect densities of perovskite films are calculated according to the formula: N t = 2e 0 e r V TFL /(qL 2 ), 42,43 where e 0 , e r , V TFL , q and L are the vacuum permittivity, the relative permittivity of the perovskite film, the trap-filled limited voltage, the basic charge and the thickness of the perovskite film, 26 respectively. As expected, the optimized device with DMITU has a lower density of defect states (3.5 Â 10 15 cm À3 ) than that of the control device (4.7 Â 10 15 cm À3 ), meaning that the DMITU facilitates the formation of excellent perovskite films, thereby reducing defect-assisted nonradiative recombination.…”

Quinoidal-type ThBF-based perovskite/HTL interface materials for efficient and stable perovskite solar cells

“…The commonly-used effective methods include (i) the addition of dopants to perovskite materials to reduce defect density, 4 (ii) the utilization of carrier transport layer (HTL) materials with high carrier mobility and fewer defects, 5 and (iii) the passivation at the interface between the perovskite and charge transport material. 6 In particular, rational design of the perovskite/HTL interface by molecular engineering can efficiently promote the hole transfer from the perovskite to the HTL. Previous research studies demonstrate that suitable small molecules, such as BSBF-NH2, 7 MT2, 8 or BTZI-TPA, 9 can effectively passivate the perovskite by interacting with Pb 2+ .…”