Hole transport layers (HTLs) play a crucial role in the efficiency and stability of perovskite solar cells (PSCs). The most efficient PSCs based on spiro-OMeTAD (Spiro) generally have stability problems. Here, NiO x /Spiro HTL has been designed and implemented by combining the advantages of these two films. The results indicated that a device based on a NiO x /Spiro HTL has faster hole extraction ability and better energy alignment than that of a pure Spiro device, thus improving the PCE from 19.8 to 21.66%. Compared with the 60% initial efficiency of Spiro-based devices, the NiO x /Spiro bilayer devices have higher stability and maintain 90% initial efficiency over 1200 h. In this work, NiO x is applied to perovskite devices with N−I−P configuration, which provides a possible mitigation strategy to reduce the V OC deficit for efficient and stable devices.

Chlorine incorporation and its configuration evolution during perovskite film formation were studied, as well as its effect on solar cell performance.

No abstract

Surface passivation is increasingly one of the most prominent strategies to promote the efficiency and stability of perovskite solar cells (PSCs). However, most passivation molecules hinder carrier extraction due to poorly conductive aggregation between perovskite surface and carrier transportation layer. Herein, a novel molecule: p-phenyl dimethylammonium iodide (PDMAI) with ammonium group on both terminals is introduced, and its passivation effect is systematically investigated. It is found that PDMAI can mitigate defects at the surface and promote carrier extraction from perovskite to the hole transporting layer, leading to a lift of open-circuit voltage of 40 mV. Profiting from superior PDMAI passivation, the average efficiency of PSCs has been elevated from 19.69% to 20.99%. As demonstrated with density functional theory calculations, PDMAI probably tends to anchor onto the perovskite surface with both NH 3 I tails, and enhances the adhesion and contact to perovskite layer. The exposed hydrophobic aryl core protects perovskite against detrimental environmental factors. In addition, the alkyl component between aryl and ammonium groups is demonstrated to be essentially vital in triggering passivation function, which offers the guidance for the design of passivation molecules.

Inverted pyramidally-textured PDMS antireflective foils for perovskite/silicon tandem solar cells with flat top cell.