Mitigation of vacancy with ammonium salt-trapped ZIF-8 capsules for stable perovskite solar cells through simultaneous compensation and loss inhibition

Abstract

Due to the easily loss nature of ions during synthesis or service process, the vacancies in perovskite film is ubiquity, which accelerate degradation of perovskite materials and seriously hamper the...

Interface Modification by FAI@ZIF‐8 for High‐Efficiency Perovskite Solar Cells

“…The addition of the FAI@ZIF-8 functional layer reduces the grain boundary defects of TiO 2 , decreases the defect density of perovskite, and promotes charge extraction and carrier transportation. [48] The ultraviolet photoelectron spectroscopy (UPS) is used to measure the surface band structure of perovskite film after the addition of the interfacial modification layer FAI@ZIF-8. It shows a good match of energy levels in Figure 7c, which the optical band gaps of the TiO 2 and perovskite are 3.3 and 1.54 eV, respectively (Figure S7, Supporting Information).…”

“…Therefore, we suppose that the FA þ and I À released from the ZIF-8 pores in the modified layer filled the iodide and formamidine ions vacancies produced during annealing of perovskite film, reducing defects and improving stability of the FAI@ZIF-8-treated device. [48] The space-charge-limited current (SCLC) method is used to quantitatively assess the surface defect density of the device with the basic structure of FTO/TiO 2 /Perovskite/PCBM/Ag, as shown in Figure 3a,b. According to Figure 3a,b, the current density linear increases at a low bias voltage region, and it was identified to be an ohmic region.…”

“…Therefore, FAI@ZIF-8 would have better performance than single ZIF-8 or FAI in fabricating efficient and stable PSCs. [48] In this study, crystal powders of α-FAPbI 3 were prepared by simple synthetic process and used as perovskite precursor. FAI@ZIF-8 was used as the interlayer between the perovskite layer and ETL to passivate grain boundary defects of perovskite, improve the energy-level distribution, and enhance the stability of the device.…”

Emerging applications of metal-organic frameworks and derivatives in solar cells: Recent advances and challenges

“…There are few reports which have demonstrated the utilization of MOFs and their derivatives as interfacial layers (interlayer) in PSCs. Three types of MOFs including ZIF-8 [204][205][206][207], a 2D conjugated MOF (ZrL3) [208], and Eu-MOF [209] were studied, while only one MOF derivative NiO@C was applied as an interfacial layer for PSC [210]. [196] These MOFs and derivatives are anticipated to enhance the perovskite crystallinity and grain size, thus further improving the photovoltaic performance of PSCs.…”

“…Wang et al demonstrated that the ZIF-8 interlayer could absorb additional light in the short-wavelength range above 350 nm, and facilitate the speed of excited electron transfer [205]; while Eslamian et al synthesized a ZIF-8 interlayer at room temperature as a scaffold to improve the perovskite grain crystallinity [206]. In addition, Zhang et al synthesized ammonium salt-trapped ZIF-8 capsules (ZIF-8 @FAI) as an interlayer between the perovskite layer and the hole transport layer (HTL) [207]. This ZIF-8 @FAI layer improved the conventional n-i-p PSC device efficiency (i.e.…”