24.96%‐Efficiency FACsPbI₃ Perovskite Solar Cells Enabled by an Asymmetric 1,3‐Thiazole‐2,4‐Diammonium

Abstract

Surmounting complicated defects at the electron transport layer (ETL) and perovskite interface plays a non‐trivial role in improving efficiency and stability of perovskite solar cells (PSCs). Herein, an asymmetric interface modification strategy (AIMS) is developed to passivate the defects from both a SnO2 ETL and the perovskite buried surface via incorporating 1,3‐thiazole‐2,4‐diammonium (TDA) into the SnO2/perovskite interface. Detailed experimental and calculated results demonstrate that N3 (the nitrogen atom bonding to the imine) in the TDA preferentially cures the free hydroxyl (OH), oxygen vacancy (VO), and the Sn‐related defects on the SnO2 surface, while N1 (the nitrogen atom bonding to the vinyl) is more inclined to passivate the Pb2+ and I− related defects at the perovskite buried surface. As a result, the TDA‐modified FACsPbI3 PSC yields a champion power conversion efficiency (PCE) of 24.96% with a gratifying open‐circuit voltage (Voc) of 1.20 V. In addition, the optimized PSCs exhibit charming air‐operational stability with the unencapsulated device sustaining 97.04% of its initial PCE after storage in air conditions for 1400 h. The encapsulated device maintains 90.21% of its initial PCE after maximum power point tracking for 500 h.

Perovskite Solar Cell Performance Boosted by Regulating the Ion Migration and Charge Transport Dynamics via Dual-Interface Modification of Electron Transport Layer

“…Accordingly, the water contact angle decreased from 17° for the SnO 2 film to 14° for the MgO/FABr-SnO 2 film (Figure S1b–g). A smaller water contact angle is known to be advantageous for the growth of PVKLs. ,, In accord, the morphological data in Figure f,g show that the dual-interface modification significantly enlarged the PVK grain size (average size: 1.20 → 2.07 μm, statistics over 10 × 7 μm 2 ). In addition, the PVK crystallinity is improved, as confirmed by the X-ray diffraction (XRD) patterns in Figure a, showing much more intense peaks for the PVKL grown on MgO/FABr-SnO 2 compared to the control.…”

“…For both the target and the control, the pair of XPS bands at 402.63 and 399.08 eV, respectively, are assigned to the adsorbed N 2 and the residual nitrate stabilizer from the SnO 2 colloidal solution. , In each case, the XPS spectrum of O 1s could be decomposed into a pair of Gaussian bands peaking around 531.85 and 530.60 eV (cf. Figure S5), which originated from the hydroxyl group (OH – ) and saturated oxygen (O 2– ), respectively. − The band-area ratio of the hydroxyl over the saturated oxygen decreases from 0.53 for SnO 2 to 0.36 for MgO/FABr-SnO 2 , proving the effective passivation of the oxygen vacancy (V O ) by the dual-interface modification.…”

Stabilizing Precursor Solution and Controlling Crystallization Kinetics Simultaneously for High‐Performance Perovskite Solar Cells

“…These results indicate that the TFFH addition enables a decrease in the energy barrier at the perovskite/TiO 2 interface, which is beneficial for electron extraction. [30] We utilized the space-charge-limited-current method (SCLC) on the FTO/TiO 2 /perovskite/PCBM/Ag cells to measure the defect density within the perovskite films (Figure 3g). [31] As shown in Figure 3g, the defect density values for the control and target devices were determined to be 1.91 × 10 16 and 9.39 × 10 15 cm −3 , respectively.…”

Toward Semitransparent PIN-type Perovskite Solar Cells with Sputtered ITO Electrode: Architecture and Process Optimizations

“…This peak could be associated with the formation of another perovskite phase with a slightly different chemical composition from the majority FACPIB perovskite phase. It would correspond well to an iodide-rich perovskite, i.e., FA 1−y Cs y PbI 3 emitting in this range, 65 indicating a possible phase separation into Br-and I-rich domains (which can also be reversible upon dark storage). However, as neither the X-ray diffractograms nor the UV−visible spectra could reveal any related difference at t 0 h , this would mean that the potential iodide-rich phases are present only in trace amounts.…”