Dual Metal‐Assisted Defect Engineering towards High‐Performance Perovskite Solar Cells

Abstract

Perovskite solar cells (PSCs) have witnessed an unprecedentedly rapid development, especially in terms of power conversion efficiency (PCE). However, the solution-processed perovskite films inevitably possess numerous crystallographic defects (e.g., halide vacancies), which has been shown to incur non-radiative charge recombination and ion migration, thus limiting the enhancement of the PCE and stability of PSCs. Here, a novel dual metal (i.e., divalent and monovalent metal ions) modification strategy is reported for simultaneously reducing the defects, immobilizing the halide anions, and preventing ion loss from perovskite during post-annealing process. Accordingly, this strategy significantly reduces non-radiative recombination, enhancing the PCE by ≈12% and mitigating the current density-voltage (J-V) hysteresis effect in resultant devices compared to undoped counterparts. As a result, a champion PCE exceeding 22% and a high open-circuit voltage (V oc ) of 1.16 V is obtained for dual metal ions-modified PSCs. The optimized devices also exhibit extended lifespan upon the dual metal treatment. The study provides a new defect engineering strategy toward more efficient and stable perovskite photovoltaics.

Chemical Reduction of Iodine Impurities and Defects with Potassium Formate for Efficient and Stable Perovskite Solar Cells

“…[ 17 ] The interstitial K + raises the energy barrier of halide ion migration, thereby inhibiting halide ion migration. [ 18 ] Furthermore, the bandgap of the perovskite films is unaffected by the introduction of HCOOK (Figure S5b, Supporting Information), and the addition of HCOOK has a minor influence on the absorption of the perovskite films (Figure S5a, Supporting Information).…”

The Impact of Multifunctional Ambipolar Polymer Integration on the Performance and Stability of Perovskite Solar Cells

“…The results indicate a decrease in potential difference after DP passivation, which provides further confirmation of the reduced defect density at the GBs achieved through this approach. [ 40 ] In addition, we determined the work function based on collected CPD data from perovskite films measured in a 2.5 µm × 2.5 µm dimension, as depicted in Figure S7 (Supporting Information). From the histogram, it is evident that the DP‐passivated perovskite films exhibit a more homogeneous work function distribution than the pristine perovskite films.…”

Low‐Temperature Synthesis of SnO2 Nanocrystals as Electron Transport Layers for High‐Efficiency CsPbI2Br Perovskite Solar Cells

“…[25][26][27][28] Intensive researches were done in grain morphology and surface defect passivation of perovskite thin films. [29][30][31][32][33][34] On the other hand, energy loss at the interface or transport layers cannot be neglected. [35] For a long period, TiO 2 is the most widely used electron transport layer (ETL) material, but its low charge conductivity and high-temperature process are adverse to acquiring efficient and stable PSCs.…”