Improve Perovskite Solar Cell Stability and Efficiency via Multifunctional Multiple‐Ring Aromatic Dopant Passivation

Abstract

Organic-inorganic hybrid halide perovskites are extensively applied in solar cells as a new absorber candidate due to their low exciton splitting energy, long carrier diffusion length, wide absorption range, and adjustable energy bandgap. [1][2][3] Represented by mixed halide MAPbI 3 perovskite, it has an appropriate tolerance factor and comparatively lower temperature required for phase transition. [4,5] It provides an excellent compromise between internal structure stability and the performance of radiation absorption (bandgap 1.8-1.93 eV). [6] It can be manufactured as a top device for constructing monolithic tandem solar cells. [7,8] According to the latest report, the power conversion efficiency (PCE) of devices with traditional single sections has climbed to 25.7%. [9] In comparison, tandem perovskite solar cells (PSCs) have a higher performance of 29.1%, [10] similar to crystalline silicon and other inorganic semiconductor solar cells. Concurrently, the traditional used solution spin coating processing and various crystallization methods are extensively utilized in the preparation of perovskite films because of the cheap cost, ease, and straightforward upgradeability. [11] PSCs have significant commercialization potential.However, perovskite films prepared using the spin-coating method may contain a large number of defects, generally regarded as recombination centers where nonradiative recombination occurs. [10,12] These unavoidable surface and boundary defects during the manufacturing process [13] severely restrict the further development of PSCs applications. [14] In addition, due to the existence of CH 3 NH 3 þ (MA þ ) cations with hygroscopic properties, [15,16] the long-term stability of devices using MAPbI 3 as the absorbent layer is poor, and they are effortless to decompose under conditions such as exposure to air, heat, and light. Therefore, passivating defects to decrease energy loss and improve the environmental stability of devices has become an urgent problem. Up to now, people have conducted extensive research on the issue of limiting the defects in PSCs and have reached certain conclusions. The studies have shown that the ester group (-COOR) can form complexes to protect FA þ , hence effectively preventing the perovskite decomposition by nucleophilic groups. [17] Moreover, by plasma crosslinking polymerization with Pb 2þ , the C═O bond in the ester group can strengthen the anchoring effect on the crystal surface. [18] As a result, the ester group, which can exert numerous passivation effects, is regarded as a significant and efficient group in improving the performance of PSCs. Sun et al. demonstrated that according to Goldschmidt tolerance factors, [19] metal ions such as K þ , [20] Rb þ , [21] Cu þ , [22] Ni 2þ , [23] Zn 2þ , [24] Al 3þ , [25] and Sb 3þ [26] are too tiny that incorporated into perovskite crystals. [10] These minor radius ions may establish

Rubidium fluoride additive for high-efficiency and low-hysteresis all-inorganic CsPbI3 perovskite solar cells

“…The Pb 4f characteristic peaks of the CsPbI 3 film appear at 138.4 eV and 143.2 eV. After doped with RbF, both peaks develop towards the ionization potential of low binding energy and occur at 138.2 eV and 143.0 eV, indicating that the electrons state of Pb has changed [28], confirming that RbF can interact with the Pb 2+ defect. Similarly, in figure 1(d), the shifted I 3d peaks (619.3 eV and 630.6 eV) toward lower binding energy to 619.0 eV and 630.3 eV illustrate that RbF can interact with I − and passivate the I − defects.…”

Polymer Poly (Ethylene Oxide) Additive for High-Stability All-Inorganic CsPbI3−xBrx Perovskite Solar Cells

“…Influenced by adding PEO, the XPS results (Figure 1b) indicated a shift towards lower binding ionization potentials for the Pb 4f 5/2 and Pb 4f 7/2 peaks. This shift suggests that the PEO allowed Pb to gain some electrons [27], hence passivating the undercoordinated Pb 2+ defects. This conclusion was consistent with previous research on polymers [28,29].…”

Minireview and Perspectives of Liquid Crystals in Perovskite Solar Cells

“…More significantly, the conjugated biphenyl systems contain delocalized π electrons and are capable of forming LC ordering by stacking, which can both efficiently improve carrier transport and control crystal orientation. Ultimately, the addition of LC8 to the perovskite film significantly improved its crystallinity, promoted charge In the next work, Ren et al 61 used a mesogenic molecule (1naphthalene acetic acid potassium salt, LC9; Figure 4) bearing a conjugated system and highly reactive carboxyl ester functionality as a dopant into MA 0.6 FA 0.4 PbI 3−x Cl x perovskite. The π conjugation and C�O bonds in the LC9 molecule create an environment that is rich in electrons, which can help with charge transfer in the layered structure and field effect passivation.…”

“…(i) Schematic portrayal of the passivation mechanism. Panels d–i were adapted with permission from ref . Copyright 2023 Wiley-VCH.…”

“…In the next work, Ren et al used a mesogenic molecule (1-naphthalene acetic acid potassium salt, LC9; Figure ) bearing a conjugated system and highly reactive carboxyl ester functionality as a dopant into MA 0.6 FA 0.4 PbI 3– x Cl x perovskite. The π conjugation and CO bonds in the LC9 molecule create an environment that is rich in electrons, which can help with charge transfer in the layered structure and field effect passivation.…”