Liquid‐State Dithiocarbonate‐Based Polymeric Additives with Monodispersity Rendering Perovskite Solar Cells with Exceptionally High Certified Photocurrent and Fill Factor

Abstract

Dithiocarbonate‐based non‐hygroscopic polymers with a glass transition temperature (Tg) and polydispersity index (PDI) of ≈4 °C and 1, respectively, are synthesized through living cationic ring‐opening polymerization. These liquid‐state polymers are characterized by monodispersity based on the low Tg and PDI, rendering remarkable miscibility with the perovskite precursors without aggregation. Accordingly, these polymers are added to perovskite solar cells (PSCs) to enhance their power conversion efficiency (PCE). The PCE of reference PSCs increases from 19.70% to 23.52% after direct addition of the synthesized polymer. This efficiency improvement is attributed to the considerable increases in short‐circuit current density (JSC) and fill factor (FF), resulting from the augmented size and defect passivation of perovskite crystals induced by added polymers. In fact, the PCE and JSC of the devices measured in the laboratory and the certification center are the highest among the reported polymer‐added PSCs, thanks to the great miscibility of the new polymers leading to the large amount addition which enables more thorough passivation among the grain boundaries. The improvement in open‐circuit voltage falls short as compared to that in JSC and FF, ascribed to the relatively moderate interaction strength between perovskite materials and dithiocarbonate groups.

Semi‐transparent metal electrode‐free all‐inorganic perovskite solar cells using floating‐catalyst‐synthesized carbon nanotubes

“…The value of n is typically between 1 and 2. An n value close to 1 corresponds to bimolecular charge carrier recombination, whereas a value close to 2 corresponds to SRH trap‐assisted recombination 85 . The Au‐ and CNT‐based devices showed relatively reasonable values of n (1.31 and 1.36, respectively).…”

Crystal Growth Nucleation Induced by CsPb2Br5 2D for Efficient and Stable Perovskite Solar Cells

“…According to earlier research, the typical (110) peak of pure MAPbI 3 , CsPbI 3 , and (100) peak of FAPbI 3 all occur at 14.20°, 14.80°, and 13.90°, respectively. [32][33][34][35] The repositioning of the characteristic peak (100) demonstrates that the composition of the perovskite film varies in response to the amount of the seed precursor. The characteristic peaks shift due to the expansion of the crystal structure brought on by the introduction of doped ions into the lattices.…”

Hydrophobic Hydrogen‐Bonded Polymer Network for Efficient and Stable Perovskite/Si Tandem Solar Cells

“…The extracted α value increases from 0.987 to 0.998 (Figure S12), further indicating that the space charge effect is virtually insignificant and almost all charges can be collected prior to recombination in the HHPN-treated cells. [55,56] We further analyzed the FF loss in PSCs, referring to the discrepancy in the SÀ Q limit (FF SQ ) and the measured FF from J-V curves, in terms of the enhanced FF by HHPN. The FF loss comprises two components -nonradiative loss and charge transport loss.…”