Stability and efficiency improvement of perovskite solar cells by surface hydroxyl defect passivation of SnO₂ layer with 4-fluorothiophenol

Abstract

Chemical bath deposited SnO2 has been widely used as an electron transport layer for high efficiency perovskite solar cells (PSCs). However, the solution processed SnO2 has -OH group on its...

Disulfidation Interfacial Engineering toward Stable, Lead-Immobilizable Perovskite Solar Cells

“…As shown in Figure (c), the trap-filled limit voltage (V TFL ) of the reference perovskite film is 0.839 V, which is decreased by passivation with PDT (0.757 V) and K2-PDT (0.558 V). Since the trap density ( n t ) is proportional to V TFL according to the relation of V TFL = e false( n t false) L 2 2 ε ε 0 , − where e is the elementary charge, L is the thickness of perovskite film, ε 0 is the vacuum permittivity (8.8542 × 10 –14 F/cm), and ε is the relative dielectric constant (determined from the impedance data in Figure S6), the decreased V TFL is indicative of a reduction in n t . The reference perovskite is estimated to be n t = 1.875 × 10 16 cm –3 , which is reduced to 1.471 × 10 16 cm –3 and 1.352 × 10 16 cm –3 after passivation with PDT and K2-PDT, respectively.…”

Effect of functional groups in passivating materials on stability and performance of perovskite solar cells

“…Dielectric constant (3 r ) was calculated by the following equation 3 r = (C g d)/ 3 0 , where C g , d, and 3 0 are the geometric capacitance, thickness of perovskite lm (thickness was determined from the alphastep proler), and vacuum permittivity (8.8542 × 10 −14 F cm −1 ). 43,44 C g is estimated from the plateau region in the capacitance-frequency (C-f) plot obtained from the same device structure (see Fig. S5(a)).…”

Highly Efficient and Stable Perovskite Solar Cells Incorporating Chlorinated-Tin Oxide Electron Transport Layers Prepared via Coordination of Diacyl-Metal Cations

“…Passivating the defects in SnO 2 ETLs with 4-fluorothiophenol prolonged carrier lifetimes and facilitated interfacial charge transfers. 34 Incorporating n-type πconjugated small molecules into the passivation layers significantly reduced the defect density and encouraged suitable band alignment with perovskite. 35,36 However, these molecules are expensive and easily oxidized in a humid atmosphere.…”

“…However, spinodal dewetting occurs during spin coating, owing to the intrinsic instability of the polymer chains in ultrathin layers (<10 nm). , Polymer-metal oxide nanocomposites were introduced to guarantee the formation of highly uniform ETLs; however, the nonconducting polymer matrix can hinder electron transport within the composite layers. , The deposition of self-assembled monolayers onto ETLs has become a more desirable strategy to ensure the uniform passivation of the surfaces. Passivating the defects in SnO 2 ETLs with 4-fluorothiophenol prolonged carrier lifetimes and facilitated interfacial charge transfers . Incorporating n -type π-conjugated small molecules into the passivation layers significantly reduced the defect density and encouraged suitable band alignment with perovskite. , However, these molecules are expensive and easily oxidized in a humid atmosphere.…”