Search

Stable and efficient planar perovskite solar cells have been demonstrated in a high relative humidity of 50% with a lead phthalocyanine (PbPc) hole-transporting layer (HTL). Porous PbI 2 film is prepared on the PbPc HTL due to it hydrophobic property, which leads to a fast formation of a compact and homogeneous perovskite film with large grains. As a result, a power conversion efficiency (PCE) of 10.79% is obtained, which is comparable to the reference device with a traditional poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) HTL and one of the highest values among the reported perovskite solar cells prepared in a high humidity condition. More importantly, the device retains 45% of its maximum PCE after it is stored in high humidity condition in dark for 56 days, comparing to an almost full failure of the reference device after only 6 days. This improvement is attributed to the restricted absorption of moisture during device fabrication and storage processes. [ABSTRACT FROM AUTHOR]

High efficiency and stable hole transporting material-free (HTM-free) planar heterojunction (PHJ) perovskite solar cells are constructed by directly thermal evaporating perovskite materials onto indium tin oxide substrate. A condense and homogeneous morphology is found for this perovskite film even without any annealing process. The optimized HTM-free CH 3 NH 3 PbI 3− X Cl X /C 60 PHJ device with a 35 nm ultra-thin CH 3 NH 3 PbI 3− X Cl X layer presents a high hole extraction efficiency and a low charge carrier recombination probability, which results in a high short circuit current and fill factor. The HTM-free device shows a high power conversion efficiency of 8.37%, which is one of the highest efficiency among reported inverted HTM-free perovskite solar cells even that a thinner perovskite film is used. More importantly, the device also exhibits a superior stability in ambient conditions. [ABSTRACT FROM AUTHOR]

Owing to their rational distribution and adequate use of the solar spectrum and a high open‐circuit voltage, perovskite/silicon‐heterojunction (SHJ) tandem solar cells can exceed the theoretical limit of efficiency for crystalline silicon solar cells. To improve the performance of perovskite/SHJ tandem solar cells, the distribution of the solar spectrum and current matching between sub‐cells must be examined and optimized. This study employs mixed perovskite as the top cell, which is prepared with pure N, N‐dimethyl formamide (DMF), pure dimethyl sulfoxide (DMSO), and mixtures of these components in different volume ratios. The effect of different solvents on surface structure and the photoelectric properties of FACs perovskite materials are systematically examined. When the volume fraction of DMSO is 40%, a smooth, well passivated, high‐quality perovskite film is obtained. Most importantly, light absorbance and transmittance are balanced by applying solvent engineering to optimize perovskite films in the tandem devices. This method can be further extended to a more complicated FAMACs perovskite/SHJ by delivering a power conversion efficiency of 22.80%. This study concludes that solvent engineering is an effective and simple method for modifying the performance of monolithic perovskite/silicon tandem devices. Through adjusting volume ratios between N‐dimethyl formamide and dimethyl sulfoxide, light absorbance and transmittance of perovskite films in tandem devices is up to balance. The effect of different solvents on surface structure and the photoelectric properties of FACs perovskite materials are systematically examined. The solvent engineering is further extended to a more complicated FAMACs perovskite/SHJ by delivering an optimal power conversion efficiency of 22.80%. [ABSTRACT FROM AUTHOR]