Incorporating Potassium Citrate to Improve the Performance of Tin‐Lead Perovskite Solar Cells

Abstract

Easy‐to‐form tin vacancies at the buried interface of tin‐lead perovskites hinder the performance of low‐bandgap perovskite solar cells (PSCs). Here, a synergistic strategy by incorporating potassium citrate (PC) into the poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) hole‐transport layer to passivate the buried interface of Sn‐Pb PSCs is reported. PC neutralizes the acidity of PEDOT:PSS and stabilizes the perovskite front surface, enhancing device stability. Citrate moieties coordinate with Sn2+ on the buried perovskite surface, preventing Sn2+ oxidation and suppressing defect formation. Additionally, potassium cations incorporate into Sn‐Pb perovskites, enhancing crystallinity and passivating halide defects. The combined benefits enable efficient low‐bandgap Sn‐Pb PSCs with a power conversion efficiency of 22.7% and a high open‐circuit voltage of 0.894 V. Using this method, 26.1% efficiency for all‐perovskite tandem solar cells is demonstrated. These results emphasize the significance of buried interface passivation in developing efficient and stable Sn‐Pb PSCs and all‐perovskite tandem solar cells.

Multifunctional Regulation of SnO2 Nanocrystals by Snail Mucus for Preparation of Rigid or Flexible Perovskite Solar Cells in Air

“…Moreover, after S-PASP treatment, the Sn 3d 3/2 (494.89 eV) and Sn 3d 5/2 (486.49 eV) peaks of the pristine SnO 2 film shifted to 494.65 and 486.23 eV, respectively. This indicates an increase in electron density around the Sn atoms and strong chemical interaction between SnO 2 and S-PASP . We performed peak fitting for the asymmetric O 1s (Figure e and Table S2) feature peaks.…”

“…This indicates an increase in electron density around the Sn atoms and strong chemical interaction between SnO 2 and S-PASP. 27 We performed peak fitting for the asymmetric O 1s (Figure 2e and Table S2) feature peaks. The proportion of adsorbed oxygen in SnO 2 is 36.86%, and the proportion of lattice oxygen is 63.14%.…”

Narrow Bandgap Metal Halide Perovskites for All-Perovskite Tandem Photovoltaics

“…It was found that incorporating potassium citrate, a weak base, into the PEDOT:PSS can not only neutralize the acidity of PEDOT:PSS but also improve the quality of the perovskites thanks to the coordination of citrate anion with the Sn(II) centers and the potassium cation enhanced film crystallinity. 382 The resultant mixed Sn−Pb PSCs show a PCE of up to 22.7% with a V OC value of 0.894 V, together with improved stability.…”

Microstress for metal halide perovskite solar cells: from source to influence and management

“…Metal halide perovskite solar cells (PSCs) have attracted much attention due to their unique photoelectric properties and power conversion efficiency (PCE), from the initial 3.8% to the certified 26.1%, 1 which is close to monocrystalline silicon solar cells. This is attributed to the small exciton binding energy and long carrier diffusion length of perovskite materials.…”