Organic solar cells with D18 or derivatives offer efficiency over 19%

In recent years,organic solar cells(OSCs)have garnered significant attention due to their distinctive attributes,such as flexibility,lightweight,and solution processing,which position them as alternatives for next-generation solar technologies[1−5].Thanks to breakthroughs in materials development,the power conversion efficiency(PCE)for single-junction OSCs has already surpassed 19%[6−13].The development of photoactive materials is pivotal in enhancing the PCEs,and several reviews have provided insights into materials design[14−18].Herein,we highlight single-junction OSCs based on D18 and its derivatives[19,20].

Crystallization and Orientation Modulation Enable Highly Efficient Doctor-Bladed Perovskite Solar Cells

With the rapid rise in perovskite solar cells(PSCs)performance,it is imperative to develop scalable fabrication techniques to accelerate potential commercialization.However,the power conversion efficiencies(PCEs)of PSCs fabricated via scalable two-step sequential deposition lag far behind the state-of-the-art spin-coated ones.Herein,the additive methylammonium chloride(MACl)is introduced to modulate the crystallization and orientation of a two-step sequential doctorbladed perovskite film in ambient conditions.MACl can significantly improve perovskite film quality and increase grain size and crystallinity,thus decreasing trap density and suppressing nonradiative recombination.Meanwhile,MACl also promotes the preferred face-up orientation of the(100)plane of perovskite film,which is more conducive to the transport and collection of carriers,thereby significantly improving the fill factor.As a result,a champion PCE of 23.14%and excellent longterm stability are achieved for PSCs based on the structure of ITO/SnO_(2)/FA_(1-x)MA_xPb(I_(1-y)Br_y)_3/Spiro-OMeTAD/Ag.The superior PCEs of 21.20%and 17.54%are achieved for 1.03 cm~2 PSC and 10.93 cm~2 mini-module,respectively.These results represent substantial progress in large-scale two-step sequential deposition of high-performance PSCs for practical applications.

26.75 cm^(2) organic solar modules demonstrate a certified efficiency of 14.34%

Organic solar cells(OSCs)have been developed rapidly in past years,due to the fast evolution of wide-bandgap copoly-mer donors and low-bandgap non-fullerene acceptors[1−9].At present,the highest power conversion efficiencies(PCEs)for single-junction OSCs and tandem OSCs exceed 19%and 20%,respectively[10,11].These OSCs are typically fabricated by us-ing low-boiling-point solvent chloroform(CF)with an effect-ive area<0.1 cm^(2).The doctor-blading deposition is the most advantageous technique to fabricate OSCs with low-boiling-point solvent for upscaling lab cells to industrial-scale mod-ules[12],exhibiting simple operation,low cost,and high materi-al utilization[13−15].Herein,a typical OSC material system PM6:Y6(Fig.1(a))was used to fabricate OSCs modules via doc-tor-blading deposition in ambient condition,and the influ-ence of the ambient temperature and substrate temperature on the film quality was investigated.

Simplified Compact Perovskite Solar Cells with Efficiency of 19.6% via Interface Engineering

For the commercialization of perovskite solar cells(PSCs), it is more appealing to develop high-performance simplified PSCs where perovskite films are just sandwiched between the back and front electrodes, in order to simplify the fabrication process and to reduce the cost. However, to date, this kind of devices shows rather low performance, and there are few researches on this subject.Herein, we report on a kind of compact PSCs(CPSCs) that are free of independent charge transport layers(CTLs). The devices are realized by the use of organic monolayer-modified effective electrodes, along with the use of [6,6]-phenyl-C61-butyric acid methyl ester(PCBM)-assisted anti-solvent technique to obtain ultra-thin(~10 nm) PCBM-embedded perovskite films. Compared to control devices, CPSCs achieve a promising champion power conversion efficiency of 19.6% with largely reduced hysteresis. Moreover, the unencapsulated CPSC shows good stability under ambient atmosphere, with only 10% efficiency loss after 60 days’ storage. This work indicates that, by delicate design, CPSCs with smaller materials consumption in device architecture can perform competitively as conventional PSCs. Further reduction in the actual usage of costly CTL materials can be expected upon our CPSCs by developing more facile and economic methods to prepare ultra-thin CTLs.

Bridging buried interface enable 24.67%-efficiency doctor-bladed perovskite solar cells in ambient condition

Scalable deposition of high-efficiency perovskite solar cells(PSCs)is critical to accelerating their commercial applications.However,a significant number of defects are distributed at the buried interface of perovskite film fabricated by scalable deposition,exhibiting much negative influence on the efficiency and stability of PSCs.Herein,2-(N-morpholino)ethanesulfonic acid potassium salt(MESK)is incorporated as the bridging layer between the tin oxide(SnO_(2))electron transport layer(ETL)and the perovskite film deposited via scalable two-step doctor blading.Both experiment and simulation results demonstrate that MESK can passivate the trap states of Sn suspension bonds,thereby enhancing the charge extraction and transport of the SnO_(2)ETL.Meanwhile,the strong interaction with uncoordinated Pb ions can modulate the crystal growth and crystallographic orientation of perovskite film and passivate buried defects.With employing MESK interface bridging,PSCs fabricated via scalable doctor blading in ambient condition achieve a power conversion efficiency(PCE)of 24.67%,which is one of the highest PCEs for doctor-bladed PSCs,and PSC modules with an active area of 11.35 cm^(2)achieve a PCE of 19.45%.Furthermore,PSCs exhibit excellent long-term stability,and the unpackaged target device with a storage of 1680 h in ambient condition(25℃and humidity of 30%relative humidity(RH))can maintain more than 90%of the initial PCE.The research provides a strategy for constructing a high-performance interface bridge between SnO_(2)ETL and perovskite film,and achieving efficient and stable large-area PSCs and modules fabricated via scalable doctor-blading process in ambient condition.

Sparkling hot spots in perovskite solar cells under reverse bias

Perovskite solar cells(PSCs)are attracting much attention and are on the way to commercialization.However,some modules are subject to reverse bias in actual fields,so it is meaningful to investigate the reverse-bias behav-ior of PSCs.Herein,an in-situ temperature and current measurement technique was developed.Intriguingly,some hot spots were observed and then quickly disappeared in the reverse biased PSCs,along with the simultaneous increase in the current and local temperature.Also,the potential mechanism has been revealed and analyzed.An abnormal bulge in the perovskite film was found at the hot spot.Accordingly,the appearance and disappearance of hot spots were perfectly explained by band bending and tunneling current caused by ion accumulation.Addi-tionally,statistical analysis suggested that sparkling hot spots were related to reverse voltage and efficiencies of PSCs.The research provides a great significance for the study of PSCs under reverse bias.