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• A complex gradient passivation strategy was first proposed for inverted PSCs. • In(SCN 2 H 4) 3 Cl 3 effectively passivates defect states in bulk perovskite layer. • In(SCN 2 H 4) 3 Cl 3 facilitates hole extraction by modulating interface energy level alignment. • The efficiency and stability of inverted PSCs are significantly improved. To address the interfacial and bulk defects and mismatched energy band alignment at perovskite/hole transport layr (HTL) interface in inverted perovskite solar cells (PSCs), here a novel In(SCN 2 H 4) 3 Cl 3 complex diffusion doping strategy was proposed to construct CH 3 NH 3 PbI 3 :In(SCN 2 H 4) 3 Cl 3 composite layer for poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine (PTAA)-based inverted PSCs. The In(tu) 3 Cl 3 effectively promotes the quality of perovskite films with larger perovskite crystal grains and flatter and denser surfaces. Both theoretical and experimental results reveal that the In(SCN 2 H 4) 3 Cl 3 can not only passivate interfacial and bulk defects in perovskite layer, but also form a spatial separation of photogenerated charges through CH 3 NH 3 PbI 3 :In(SCN 2 H 4) 3 Cl 3 heterojunction interface, which effectively decreases the charge recombination and enhances charge separation and transport property in PSCs. Moreover, the In(SCN 2 H 4) 3 Cl 3 optimizes energy band alignment at perovskite/PTAA interface and creates a polarization electric field at the PTAA/In(SCN 2 H 4) 3 Cl 3 interface directing toward PTAA layer, which promotes the hole transfer from the CH 3 NH 3 PbI 3 to the PTAA and increases the open-circuit voltage (V oc). As a consequence, optimized inverted PSCs with CH 3 NH 3 PbI 3 :In(SCN 2 H 4) 3 Cl 3 layer achieve high efficiency of 21.25 % and also show a significantly improved long-term stability under different aging test conditions. Our work provides a valuable guide for designing efficient and stable inverted PSCs. [ABSTRACT FROM AUTHOR]

C@Fe 2 C/TiO photocatalytic CO 2 realizes C–C coupling to produce C2 fuel mainly due to the formation of a Z-scheme heterojunction between Fe 2 C and TiO, which changes the electron transmission path, and the CO* generated by TiO induces the production of C2. [Display omitted] • A novel C@Fe 2 C/TiO ternary composite catalyst is prepared. • The catalyst exhibits high activity under simulated sunlight with main-product of C 2 H 4. • The catalyst could be excited by NIR lights. CO 2 conversion is of great industrial importance in reducing green-house effect and reusing carbon-resource. Most studies are focused on the thermocataltic CO 2 conversion, which usually performs over noble metal catalysts at high temperature and pressure. Recently, photocatalytic CO 2 conversion has caused increasing attention owing to the energy save, low-cost and clean reaction route. The key problem is to design photocatalysts high activity and strong durability. Here, we choose to prepare a novel C@Fe 2 C/TiO ternary composite catalyst by reducing organic compounds under an ammonia atmosphere. During CO 2 reduction reaction in aqueous solution, the catalyst exhibits high activity under simulated sunlight with main-product of C 2 H 4 (35.483 μmol g-1h−1). Even irradiating with near-infrared lights, the catalytic conversion still proceeds successfully, but the main-product turns to be CH 4 (18.315 μmol g-1h−1). Based on the chanracterizations and DFT calculation, the high activity could be attributed to the cooperation between the Fe 2 C catalyst toward C 2 H 4 and the TiO 2 photocatalyst. Specially, C@Fe 2 C/TiO could be excited by NIR lights owing to the narrow-energy band gap. More importantly, the photoelectrons could be easily separated from holes owing to the presence of the Z-scheme heterojunctions, leading to the enhanced photocatalytic activity. This work provides new insights to understand the CO 2 reduction reaction mechanism to develop photocatalysts. [ABSTRACT FROM AUTHOR]