Crystallization Control of Ternary‐Cation Perovskite Absorber in Triple‐Mesoscopic Layer for Efficient Solar Cells

Abstract

Controlling the crystallization of organic–inorganic hybrid perovskite is of vital importance to achieve high performing perovskite solar cells. The growth mechanism of perovskites has been intensively studied in devices with planar structures and traditional structures. However, for the printable mesoscopic perovskite solar cells, it is difficult to study the crystallization mechanism of perovskite owing to the complicated mesoporous structure. Here, a solvent evaporation controlled crystallization method to achieve ideal crystallization in the mesoscopic structure is provided. Combining results of scanning electron microscope and X‐ray diffraction, it is found that adjusting the evaporation rate of solvent can control the crystallization rate of perovskite and a model for the crystallization process during annealing in mesoporous structures is proposed. Finally, a homogeneous pore filling in the mesoscopic structure without any additives is successfully achieved and a stabilized power conversion efficiency of 16.26% using ternary‐cation perovskite absorber is realized. The findings will provide better understanding of perovskite crystallization in printable mesoscopic perovskite solar cells and pave the way for the commercialization of perovskite solar cells.

Low‐Dimensional Contact Layers for Enhanced Perovskite Photodiodes

“…Photodiodes comprising metal halide perovskites have demonstrated extraordinary potential for practical applications. [ 1–4 ] The last few years have witnessed an explosive growth of interest in perovskite solar cells [ 5–7 ] and light‐emitting diodes [ 8–10 ] because of their outstanding device performance and ease of fabrication. Recently, perovskites have also shown their superiority in light signal detection (photodetectors), [ 11,12 ] comparable to those of commercially available crystalline Si photodetectors.…”

In situ transfer of CH3NH3PbI3 single crystals in mesoporous scaffolds for efficient perovskite solar cells

“…26,31 Previously, we have developed a MA 0 gas post-treatment method to enhance the performance of MAPbI 3 based cells. 20 The MA 0 gas can make the morphology of the perovskite more uniform and compact. Correspondingly, an average efficiency of over 14% was achieved (champion efficiency of 15.26%).…”

“…6 It has been proposed that the MA 0 gas treatment of MAPbI 3 induces rapid defect-healing of perovskite lms at room temperature. [18][19][20][21] In this process the lone-pair electrons on N in the MA 0 molecule interact with the octahedral framework of PbI 6 4À in MAPbI 3 .…”

Post‐Treatment of Mesoporous Scaffolds for Enhanced Photovoltage of Triple‐Mesoscopic Perovskite Solar Cells

“…Decent efficiencies can be obtained on the condition that the perovskite precursor is converted to perovskite crystals with desired phases. [ 27–29 ] However, the open‐circuit voltage ( V OC ) is always much lower than that of traditional PSCs, which limits the further improvement of the PCE of triple‐mesoscopic PSCs. Considering the unfavorable band alignment due to the absence of HTMs, we have attempted to increase the work function of the carbon electrodes by boron‐doping to enhance the photovoltage of the devices, [ 30 ] and reduce the potential loss at the carbon/perovskite interface by post‐treatment with high work function inorganic nanoparticles.…”