Themed collection FOCUS: Recent Progress on Perovskite Solar Cells, 2021-2022

This review summarizes the latest research progress on strategies for lead leakage control in perovskite solar cells to facilitate the future development of efficient, stable, and environmentally friendly perovskite photovoltaic devices.

Metal halide perovskite solar cells (PSCs) continue to improve their power conversion efficiency to over 25.5%, which is at the same level as silicon solar cells.

This review summarized the different strategies of enhancing the perovskite mechanical stability, and we mainly describe from three aspects: mechanical stability of perovskite layer, interface engineering and engineering on other functional layers.

Flexible perovskite-based tandem solar cells could be the game-changer for next-generation flexible photovoltaics.

This review presents critical advances of perovskite-based tandem solar cells (TSCs). Electrode engineering, interface engineering, bandgap engineering, and processing techniques are discussed, as well as the future directions and challenges.

We summarized the recent reported strategies for overcoming the challenges for lead-free tin halide perovskite solar cells (THPSCs), expecting to give a perspective outlining the possible future direction for THPSCs.

This review discusses the latest progress in improving the performance and stability of CsPbI₃ PSCs based on the metastable phase.

A carbolong derivative with a M-PCCO framework was employed as the cathode interlayer, boosting the performance and stability of inverted PSCs.

A novel organic-inorganic hybrid rear window layer (RWL) was constructed. The photoelectric balance of the hybrid RWL was improved by doping with 1T-phase WS₂ (1T-WS₂).

Photo-induced charge carrier dynamics over a wide time domain from sub-nanoseconds to microseconds, via time-correlated single photon counting and flash photolysis time-resolved microwave conductivity measurements.

Novel cyan-green emitting Eu²⁺ doped K₂HfSiO₅ phosphors were synthesized and applied in CsPbI₃ perovskite solar cells as an energy-down-shift layer.

D–π–D hole-transporting materials are designed via facile approaches for efficient perovskite solar cells. Suitable band alignment and high hole mobility by strengthening the conjugation in the core allow effective hole extraction.

In this contribution, PSCs with a high efficiency and good stability are fabricated under ambient conditions without a glove box via introducing triethyl phosphate (TEP) into a perovskite through an antisolvent.

A type of comparatively flexible binaphthyl-ether structured polymer, which reveals high device thermal-durability, is reported.

We have developed a novel HTM named SPS-SPX-2TPA for perovskite solar cell applications. This HTM showed the best PCE of 17.39% and maintained 95% of their initial PCE even after 600 h. It is three times cheaper cost than the Spiro-OMeTAD HTM.

Graphdiyne oxide-doped SnO₂ is applied as a novel electron transfer layer for the preparation of high-performance perovskite devices.

Most organic hole-transport materials (HTMs) toward efficient perovskite solar cells (PSCs) thus far still rely on methoxytriphenylamine, which limits the photovoltage and decrease the stability of PSCs.

In this work, a new small molecular material, 9,9′-(pyrene-1,6-diyldimethylylidene)bis[N,N,N′,N′-tetrakis(4-methoxyphenyl)-9H-fluorene-2,7-diamine] (PFD), as a hole-transporting layer was designed for perovskite solar cells (PSCs).

This study employs mixed formamidinium/methylammonium (FA/MA) organic cations as an efficient perovskite layer, resulting in a champion PCE of up to 19.50%, one of the highest efficiencies yet reported for ambient air-processed PSCs.

Potassium salts modified NiO_X could improve the perovskite film coverage and reduce trap densities, so as to improve device performance.

Three different benzylammonium halide (Cl, Br, and I) salts were investigated to elucidate their effects as additives on MAPbI₃ perovskite surface morphology, crystal structure, optical properties, and solar cell performance and stability.

Zinc acetate (ZnAc₂) is employed as an additive for the first time to form a FAI·SnI₂·ZnAc₂ intermediate phase to enlarge grain size and suppress Sn²⁺ vacancies of FASnI₃ films due to the synergetic effects of Zn and Ac ions.

Three cost-effective D–π–D hole-transport materials were synthesized for use in perovskite solar cells. The (FAPbI₃)_0.85(MAPbBr₃)_0.15 and CsPbI₂Br solar cells with SY3 gave PCEs of 19.08% and 13.41%, respectively.

n-i-p perovskite devices based on NDI materials are fabricated to demonstrate utility of a transparent polymer vs. that of several small molecules with varied acceptor strengths; stable solar cells with 14% PCE are reported.