Tin‐based perovskite solar cells (TPSCs) have become a star candidate in lead‐free perovskite cells due to their excellent optoelectronic properties and low toxicity. However, there are a lot of problems such as uncontrollable crystallizationprocess, easy oxidation of Sn2+ and high defect density have not been completely resolved in TPSCs. Here, the thiourea (TU) and amidine thiourea (ASU) are added into the perovskite precursor to regulate the microstructure, inhibit the oxidation of Sn2+ and promote charge transfer. The characterization results demonstrate that the TU additive can not only improve the micrograph, crystallinity and antioxidant, but also significantly induce recrystallization and passivate trap states. Thus, the TPSCs with TU (TU‐modified TPSCs) show a significantly higher power conversion efficienc (PCE) and better stability than those of the TPSCs with ASU (ASU‐modified PSCs) and reference TPSCs. After stored in N2 atmosphere for 8 months, the unencapsulated TU‐modified PSCs achieve a champion PCE of 10.9% with an open‐circuit voltage of 0.79 V. Furthermore, the unsealed TU‐modified PSCs can maintain 115% of its initial efficiency after stored in N2 atmosphere for one year. This is the longest lifetime of unencapsulated pure TPSCs in N2 atmosphere.

To improve the microstructure of low-temperature-processed CsPbIBr2 films, a chlorobenzene (CB) and isopropyl alcohol (IPA) mixed solution is used as an antisolvent to fabricate CsPbIBr2 films. It is found that the modified film by the mixed antisolvent demonstrates a better morphology, crystallinity, absorption of sunlight, less trap-state density (N trap), and suppressed carrier recombination. The modified perovskite solar cells (PSCs) without a hole-transport layer (HTL) achieve a champion efficiency of 7.05%, being much higher by 28.18% than that of the Reference-PSCs without an antisolvent. Moreover, the HTL of undoped zinc phthalocyanine (ZnPc) prepared by solution processing is used to promote charge transfer and protect the CsPbIBr2 film from damage caused by humid air at the CsPbIBr2/carbon interface. The best PSC with a structure of FTO/TiO2/CsPbIBr2/ZnPc/carbon yields a champion efficiency of 8.48% (Reference-PSC, 5.50%) with an open-circuit voltage of 1.23 V. The modified PSCs without encapsulation demonstrate improved humidity stability and retain about 90% (Reference-PSC, ∼70%) of their initial efficiency after storage at a 20% relative humidity in air for 30 days. In addition, the modified PSCs possess good light and thermal stability. Our work provides a feasible low-temperature (150 °C) process to prepare CsPbIBr2 films with the preferred orientation and stable, efficient all-inorganic PSCs (200 °C).

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