Formamidinium lead triiodide （FAPbI3） is a promising photoactive perovskite for low-cost and efficient solar cells. This article reports on an experimental investigation on the stability of FAPbI3 by ...comparison with that of widely-used methylamidinium lead triiodide （MAPbI3）. A hydration of the FAPbI3 with mois- ture could be the dominant mechanism for its degradation in air, rather than a common thermal decom- position in the MAPbI3. This can be mainly contributed to a relatively strong bond formation between formamidinium ions （FA＋） and 1-. Consequently, the stability of FAPbl3 based devices can be greatly enhanced by removal moisture in the surrounding. This conclusion renders FAPbI3 extremely attractive for stable perovskite solar cells with fine encapsulation.
Three-dimensional halide-based perovskites have emerged as promising semiconducting light harvesters for thin-film solar cell fabrication; however, their intrinsic instability under humidity ...restricts their potential commercialization. To address such challenges, the development of low-dimensional/layered Dion–Jacobson (DJ) phase perovskites has recently gained substantial attention due to their intriguing environmental stability and competitive power conversion efficiency. In this Review, we have screened and focused our investigation on the DJ phase in layered perovskites for solar cell fabrication, especially elucidation of the active role played by organic spacer cations. We also discuss the possible strategies that can be employed to further push the performance of DJ-based perovskite solar cells.
Nowadays hole-transporting materials based on conductive small organic molecules and polymers have become the hottest topic in high-performance perovskite solar cells. Currently, the perovskite solar ...cells have reached certified power conversion efficiency of 22.1%. 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene and poly-triarylamine are the two widely used hole-transporting materials in highly efficient perovskite solar cells. It is highly desirable to seek other low-cost and efficient hole-transporting material for highly efficient and stable perovskite solar cells. This review summarizes recent progress of typical small molecules, conductive polymer hole-transporting materials used for efficient perovskite solar cells. Particularly, we focus on those hole transporting material based on triphenylamine units.
•Hole-transporting material plays an indispensable role in charge extraction and transportation.•Organic hole-transporting material has become the hottest topic for perovskite solar cells.•Explore novel material with complementary light absorption would be significant to improve the current density.
A single walled carbon nanotube (SWCNT) possesses excellent hole conductivity. This work communicates an investigation of perovskite solar cells using a mesoscopic TiO2/Al2O3 structure as a framework ...in combination with a certain amount of SWCNT-doped graphite/carbon black counter electrode material. The CH3NH3PbI3-based device achieves a power conversion efficiency of 14.7% under AM 1.5G illumination. Detailed investigations show an increased charge collection in this device compared to that without the SWCNT additive.
Recently, acceptor–donor–acceptor (A–D–A) small molecules have emerged as promising nonfullerene acceptors (NFAs) for organic solar cells and have attracted great attention. The carbon‐bridged ...(C‐bridged) ladder‐type D unit plays a crucial role in developing high‐performance A–D–A NFAs. However, the medium electron‐donating capability of C‐bridged units is unfavorable for making NFAs with strong light‐harvesting capability. In this regard, carbon–oxygen‐bridged (CO‐bridged) ladder‐type units present advantages in developing strong light‐absorbing NFAs. Here, recent progress in the newly emerging CO‐bridged NFAs is highlighted. The synthetic methods for the polycyclic CO‐bridged building blocks are introduced. The photovoltaic performance for CO‐bridged NFAs is summarized and discussed. Perspectives on developing high‐performance CO‐bridged‐NFA‐based solar cells are made.
Thanks to the strong electron‐donating capability of carbon–oxygen‐bridged (CO‐bridged) ladder‐type building blocks, CO‐bridged nonfullerene acceptors (NFAs) present low bandgaps and strong light‐harvesting capability, delivering high short‐circuit current density (>28 mA cm−2) and high power conversion efficiency (>14% for single‐junction and >17% for tandem) in organic solar cells.
In the present work, we report on a two-step vapor deposition (TVD) process of depositing graphitic carbon nitride (g-CN) films for photoelectrochemical (PEC) application. The method is versatile for ...various monomers including cyanamide, dicyanamide and melamine as well as different substrates. The role of deposition temperature and amount of monomers has been investigated in detail. Structural and surface morphological studies suggest uniform and pinhole-free g-CN films could be achieved with this feasible method. Photon-induced oxygen evolution upon anodic polarization in aqueous electrolytes brings up a photocurrent density of 63 μA cm−2 for the g-CN films prepared with dicyanamide. This is the highest value to date for a pristine g-CN photoanode at the bias of 1.23 V (versus reversible hydrogen electrode) without sacrificial reagents. The good performance could be attributed to an enhanced light harvesting and decreased charge transport resistance at the film/electrolyte interface with an increase of amount of monomers. Accordingly, the strategy of TVD brings g-CN another step to applying as photoactive material in various photoelectronic fields. Furthermore, this method can also be easily extended to synthesis of heterojunction in the second-step of TVD process by choosing proper substrates to further enhance the PEC properties.
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We present efficient perovskite solar cells using a mesoscopic TiO2/Al2O3/NiO/carbon structure as framework. The CH3NH3PbI3-based device with quadruple-layer architecture achieves a power conversion ...efficiency of 15.03% under AM 1.5G illumination. Detailed investigations show an increased charge collection and reduced charge recombination in this device structure compared to that without NiO interlayer. It is found that these perovskite solar cells exhibit good stability both in dark and under illumination.
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•Efficient perovskite solar cell using mesoscopic TiO2/Al2O3/NiO/carbon architecture as framework.•The CH3NH3PbI3 device achieving a power conversion efficiency of 15.03% under AM 1.5G illumination.•The perovskite solar cell exhibiting good stability both in dark and under illumination.
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