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In this work, cesium salts with functional anions of acetate (Ac−), fluoride (F−) and trifluoroacetate (TFA−) are explored to modulate the deposition of ZnO films in low-temperature carbon-based CsPbI2Br perovskite solar cells.

Hydrophobic organic ammonium halide salts are used to passivate perovskite defects, adjust interfacial energy level alignments, and ultimately improve the efficiency and stability of low-temperature carbon-based CsPbI2Br perovskite solar cells.

We report a solution-processed method to prepare inorganic LaNiO3 (LNO) hole-transport layer (HTL) under low temperature (

The charge recombination resulting from bulk defects and interfacial energy level mismatch hinders the improvement of the power conversion efficiency (PCE) and stability of carbon-based inorganic perovskite solar cells (C-IPSCs). Herein, a series of small molecules including ethylenediaminetetraacetic acid (EDTA) and its derivatives (EDTA-Na and EDTA-K) are studied to functionalize the zinc oxide (ZnO) interlayers at the SnO

Defective grain boundaries (GBs) and surface trap states are detrimental to the efficiency and stability of perovskite solar cells (PSCs). In this research, ionic liquid (IL) is used to control the defect states at the perovskite surface and GBs. The newly formed (EMIm)xMA1-xPb[(BF4)xI1-x]3 interlayer promotes secondary grain growth to diminish GBs; besides, EMIM+ and BF4- fill the vacancies of MA+ and I- and also passivate undercoordinated Pb2+ trap states. The newly formed interface largely reduces the nonradiative recombination, thus enhancing the solar-cell performance to 19.0% (AM 1.5, 1 sun) with higher photovoltage and fill factor than the control device. Due to the hydrophobicity of the (EMIm)xMA1-xPb[(BF4)xI1-x]3 interlayer, the unencapsulated device stability in 30 days is much better than the control device under relative humidity (RH) = 20%. This work highlights IL-induced secondary grain growth and a defect passivation method for efficient and stable PSCs.

In perovskite solar cells (PSCs), a defective perovskite (PVK) surface and cliff-like energy offset at the interface always slow down the charge extraction; meanwhile, interface ion diffusion causes oxidation of the metal electrode, inducing device instability. Here, the in situ grown 2D-(CH

Defective grain boundaries (GBs) and surface trap states are detrimental to the efficiency and stability of perovskite solar cells (PSCs). In this research, ionic liquid (IL) is used to control the defect states at the perovskite surface and GBs. The newly formed (EMIm)

In inverted perovskite solar cells, the [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)/Ag back interface is quite important because serious recombination occurs and H2O/O2 directly attacks this interface to induce device instability. Here, bi-functional dipole layers are applied at the interface aiming at improving the charge transport and device stability simultaneously. Silane with -CF3 end group anchored on the PCBM surface induces more effective dipole effect than that with (CH2)7-CH3 end functional silane, bending the interface energy level to promote electron transport and reduce recombination. The hydrophobic nature of -CF3 also enhances the durability of the device. This work highlights the back surface dipole management method to achieve efficient and stable perovskite solar cells.

In perovskite solar cells, the Lewis acid-base additives function effectively in high crystalline perovskite film formation and defects passivation. Exploration of effective Lewis acid-base additive to prepare high quality inorganic CsPbI2Br perovskite films with few defects is quite imperative. Here, thioacetamide with S-donor and acetamide with O-donor as Lewis base additives are investigated. It is revealed that a high electron density on S results in better coordination ability with Pb2+ in perovskite solution, leading to form high crystallinity film with lower defect states compared with O-donor. The inorganic CsPbI2Br based perovskite solar cells with thioacetamide additive exhibit the best performance of 15.87% (AM 1.5, 1 sun) and good ambient stability compared with the control device and device with acetamide. This work provides guidance for choosing and designing the effective additives for perovskite solar cells.

In perovskite solar cells, the molecule configuration of Lewis adducts closely related with its coordination ability, which needs careful design. In this work, two amino acids, circular proline and linear glycine are applied to reveal the steric effect of the Lewis-acid base additives. The proline with configuration and analogous size with Pb-Pb distance in perovskite crystals realizes better coordination effect, greatly promotes the perovskite crystal growth and trap states passivation. The PSCs with proline as additives in perovskite (PVK) exhibit the highest efficiency of 19.6% under 1 sun AM1.5, compared with 18.5% of PSC with glycine additive and 17.8% of the pristine PSCs. This work highlights steric effect should be considered when choosing and designing the Lewis adducts.

NiO ink fabricated perovskite solar cells (PSCs) is attracting increasing attention due to the simple preparation process and the low processing temperature. Ascribing to the easy aggregation property of the nanoparticles, it is quite important to fabricate high quality NiO ink with high crystallinity and good dispersity. In this work, the function of the anions to the nanoparticles (NPs) formation is discussed. It is found out that suitable electrostatic interactions between the NO3− and Ni2+ lead to high crystallinity and well dispersion of the NiO NPs. The high quality NiO ink fabricated by Ni(NO3)2 results in high quality NiO HTL and perovskite on it. The perovskite solar cell device using Ni(NO3)2 fabricated NiO HTL exhibits performance of 18.4% with good reproducibility and stability, much higher than 16.3% of PSCs with NiCl2 fabricated NiO layer. This work highlights an anion influenced NiO NPs’ formation process, which is quite illuminating to the fabrication of high performance PSCs.