Sulfonyl and Carbonyl Groups in MSTC Effectively Improve the Performance and Stability of Perovskite Solar Cells

Abstract

Intrinsic defects are key factors that would affect the performance and stability of perovskite solar cells (PSCs). Herein, a sulfonamides additive, methyl 3‐sulfamoyl‐2‐thiophenecarboxylate (MSTC), is introduced into the PbI2 or FAI/MACl/MABr precursor solution, to prepare high‐quality PSCs with a two‐step method. After the addition of MSTC, all the devices show enhanced performance. With optimized MSTC incorporated into PSCs, the champion power conversion efficiency (PCE) of the PSCs is increased from 19.19% to 22.14%, and the stability is also improved. The MSTC‐FAI based device can still maintain 89% of its initial PCE compared to 68% of the control one after 15 days in ambient condition under relative humidity of 40–50% at room temperature in dark. Test results reveal that amido group in MSTC would coordinate with PbI2 or FAI through hydrogen bonding (NH···I), thus effectively enhancing the performance of devices. Nevertheless, the sulfonyl and carbonyl groups in MSTC would coordinate with the FAI precursor through chemical bond of COS and COC. And with the hydrogen bonding connection between MSTC and FAI, the inherent defects in the MSTC‐FAI based device are effectively suppressed, leading to the enhanced photovoltaic performance.

Enhanced Bending Resistance and Efficiency of Flexible PSCs Derived from Self‐Healing and Passivation Double Function of a Silane Coupling Agent

“…Where ε o is the vacuum permittivity, ε r (46.9) is the relative dielectric constant, V TFL is the onset voltage of the trap-filled limit region, q is the elemental charge, and L is the thickness of perovskite film (850 nm, obtained from SEM). [36] The V TFL value of the control and VTMES modified device is 1.56 and 0.98 V, respectively. Thus, the statistic N t significantly decreases from 4.75 × 10 16 to 2.99 × 10 16 cm -3 for the control and modified devices, respectively.…”

“…The much weaker Si-O peak of the modified perovskite film compared to VTMES manifest that VTMES connected with perovskite by forming PbO bonding due to oxydic properties of ionic oxygen atoms. [28,36] In addition, Figure S2 (Supporting Information) shows X-ray photoelectron spectroscopy (XPS) of control and modified perovskite films. Pb 4f peaks shift from 138.20 and 143.10 eV to 138.41 and 143.25 eV (Figure S2b, Supporting Information), and O 1s peak shift from 532.34 to 532.56 eV (Figure S2c, Supporting Information) for control and VTMES-modified films, respectively.…”

“…The shift of Pb 4f and O1s indicates that Pb 2+ can coordinate with O atoms in VTMES since the lone pair of O electrons can fill vacant orbitals of unsaturated Pb 2+ . [36] X-ray diffraction (XRD) patterns of perovskite films with different VTMES concentrations are shown in Figure 2a. It can be concluded from Figure 2a that no new peaks appear after VTMES is modified.…”

Consolidating a Pb–X framework via multifunctional passivation with fluorinated zwitterions for efficient and stable perovskite solar cells

“…The reason is that a synergistic effect from zwitterions and fluorine functional groups in D-PPFAA inhibits the formation of PbI 2 . 40 Moreover, new peaks do not appear and peak shifts do not occur, indicating that D-PFPAA molecules are not incorporated into the perovskite lattice, only existing at the perovskite surface or at GBs. 41 As verified via Fourier-transform infrared (FTIR) spectra (Fig.…”

High Moisture Stability for Enhanced Quality Perovskite Solar Cells Induced by Front and Back Layer Synergistic Passivation of Perovskite

“…With the addition of TBBS and PTAA, CPD of the perovskite films increases sequentially, reaching up to 776 mV; the enhanced CPD is related to reduction of surface defects and reduced charge recombination at GBs, thus improving the electrical conductivity of the interface between PVK and HTL, which is more conducive to charge transmission and improvement of FF in PSCs. [15,27] Carrier transportation is often related to energy level matching. [28] Therefore, in order to further explore energy level between HTL and perovskite, ultraviolet photoelectron spectroscopy (UPS) is characterized.…”