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The performances of perovskite solar cells (PSCs) largely depend on the perovskite compositions and the selection of electron and hole transport layers (ETLs and HTLs). The p‐type NiO x films are largely used as HTLs in p‐i‐n PSCs, thanks to their high transparency, processing versatility, cost‐effectiveness, and easy integration within tandem devices. Several studies have shown that surface modifications on NiO x films remove the surface defects, increase the NiO x conductivity, and alter the band offset, consequently improving the interfaces between NiO x films and the perovskite active layer. Indeed, besides improving the NiO x intrinsic properties, the surface treatments also lead, in many cases, to superior perovskite quality driving high photovoltaic performance.

In this work, we explore the potentials and the characteristics of electron‐transporting layers (ETL) grown by atomic layer deposition (ALD) at low temperature in co‐evaporated perovskite solar cells (PSCs). The thermal‐based ALD process has been investigated by tuning the main growing conditions as the number of cycles and the growth temperature. We show that un‐annealed ALD‐SnO2 thin films grown at temperatures between 80 °C and 100 °C are efficient ETL in n.i.p co‐evaporated MAPbI3 PSCs which can achieve power conversion efficiencies (PCEs) consistently above 18%. Moreover, the champion PSC achieved a PCE of 19.30% at 120 °C with 150 cycles. We show that the low‐temperature processed ALD SnO2 is very promising for flexible, large‐area PSCs and mini‐modules. We also report the first co‐evaporated PSCs employing low temperature processed ALD ZnO with PCEs approaching 18%. This work demonstrates the potential of the low‐temperature ALD deposition method as a potential route to fabricate efficient PSCs at low temperatures.

Advances and potentials of NiOx surface treatments for p-i-n perovskite solar cells. Solar RRL, 6(3), 2100700-, which has been published in final form at https://doi.org/10.1002/solr.202100700. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.

Perovskite solar cells (PSCs) have attracted great interest over the past few years due to their outstanding power conversion efficiencies. However, operational stability still needs to be improved for broad commercial application. A commonly observed phenomenon for PSCs is hysteresis in their current–voltage characteristics, which has been suggested to be related to issues with long‐term stability. A thorough understanding of the processes involved in hysteresis may also guide the way to further improving the cells’ efficiencies. We fabricate planar p–i–n organic–inorganic hybrid PSCs using three different organic transport layer architectures by vacuum deposition and measured their hysteresis and long‐term stability behavior. Our results show that vacuum‐deposited PSCs show much weaker hysteresis than in previous studies, where many types of PSCs were involved. For our devices, we also report an inverted hysteresis, where efficiency is somewhat higher for a voltage sweep from short circuit to forward‐bias conditions than for the reverse sweep at lower scan rates, which has not commonly been observed in previous studies of PSCs. Finally, we observe that up to 94 % of the initial power conversion efficiency of the encapsulated devices remained after storage in the dark for two months.

The versatile nature of organic conjugated materials renders their flawless integration into a diverse family of optoelectronic devices with light-harvesting, photodetection, or light-emitting capabilities. Classes of materials that offer the possibilities of two or more distinct optoelectronic functions are particularly attractive as they enable smart applications while providing the benefits of the ease of fabrication using low-cost processes. Here, we develop a novel, multipurpose conjugated small molecule by combining boron-azadipyrromethene (aza-BODIPY) as electron acceptor with triphenylamine (TPA) as end-capping donor units. The implemented donor-acceptor-donor (D-A-D) configuration, in the form of TPA-azaBODIPY-TPA, preserves ideal charge transfer characteristics with appropriate excitation energy levels, with the additional ability to be used as either a charge transporting interlayer or light-sensing semiconducting layer in optoelectronic devices. To demonstrate its versatility, we first show that TPA-azaBODIPY-TPA can act as an excellent hole transport layer in methylammonium lead triiodide (MAPbI 3 )-based perovskite solar cells with measured power conversion efficiencies exceeding 17%, outperforming control solar cells with PEDOT:PSS by nearly 60%. Furthermore, the optical bandgap of 1.49 eV is shown to provide significant photodetection in the wavelength range of up to 800 nm where TPA-azaBODIPY-TPA functions as donor in

This cover (DOI: 10.1002/inf2.12345) shows a multifunctional TPA‐azaBODIPY‐TPA small molecule with superior optoelectronic and photophysical properties. Material is shown to function as an efficient hole transport layer in perovskite solar cells reaching a power conversion efficiency of 17.4%, and as a robust electron donor in near‐infrared organic photodetectors absorbing light in the wavelength range of up to 800 nm. Offering two distinct optoelectronic functions, TPA‐azaBODIPY‐TPA is particularly attractive as it enables multi‐purpose applications while maintaining the ease of fabrication. image

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