Search

[Display omitted] • Bilateral passivation strategy by PEACl doping and NPB post-treatment is proposed. • Construction of GHJ provides a favorable transport pathway for hole migration. • Achieving a PCE of 21.88% for PEACl-SnO 2 -NPB based PSCs with negligible hysteresis. • Improved moisture and thermal stability of PSCs by using synchronous regulation. Defects and inferior charge transport dynamics within devices are key issues that inhibit the improvements of photovoltaic performance and stability. Developing facile and feasible strategies for synchronous passivation of defects regarding charge transport layers (CTLs), perovskite films and their interfaces, and precise tuning of energy level structure, is a definite way to solve above problems. Herein, we develop a synergistic passivation strategy for perovskite films and bilateral interfaces to improve device performance. Firstly, an appropriate amount of phenylethylammonium chloride is adopted to modify SnO 2 electron transport layer (ETL). The complexation reaction between N atoms in –NH 2 and Sn4+ improve the agglomeration of SnO 2 nanoparticles and film quality of SnO 2 ETL. The presence of Cl− ions not only effectively fill oxygen vacancies within SnO 2 ETL, but also participate in regulating crystal growth dynamics of perovskite films, thus improving electron transport properties at interface. Subsequently, p-type conducting material N,N'-Bis-(1-naphthalenyl)-N,N'-bis-phenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) is introduced into anti-solvent chlorobenzene during the preparation of perovskite films to further regulate the crystal quality and achieve full-range defect passivation. Particularly, the introduction of NPB helps to construct a gradient heterojunction between upper perovskite film and SpiroOMeTAD hole transport layer, thus reducing the accumulation of hole carriers near interface and further suppressing current–voltage hysteresis behavior of devices. Additionally, the hydrophobicity of NPB and full range of defect passivation greatly enhance the humidity and thermal stability of devices. Finally, a high power conversion efficiency of 21.88% is obtained with suppressed hysteresis and enhanced long-term stability. This work highlights the role of full-range defect passivation on CTLs, perovskite absorption layers and interfacial charge transport properties, which provide a novel concept for constructing high-performance and stable perovskite devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Iodine ligand-coupled PbS QDs film was firstly used to modify ZnO ETLs to boost photovoltaic performance of PSCs. • Introducing PbS-TBAI layer improves crystal quality of perovskite and forms cascade energy band structure. • A maximum PCE of 20.53 % has been achieved in the PSCs based on ZnO/PbS-TBAI-80 ETLs. Zinc oxide (ZnO) was traditional cathode material for solar cells due to excellent photoelectric properties. However, when ZnO is used as electron transport layers (ETLs) in perovskite solar cells (PSCs), the occurred deprotonation reactions can easily lead to the decomposition of perovskite layer. Herein, we reported a simple and controllable low-temperature strategy to overcome above problem for achieving high-efficient and stable ZnO based planar PSCs, i.e. the colloidal PbS QDs and tetrabutylammonium iodide (TBAI) was sequentially spin-coated on ZnO ETLs and then mild post-annealing process was carried out to obtaining ZnO/PbS-TBAI compact layer. Due to the iodine ligands from TBAI, the PbS-TBAI films act as both surface wetting control layer and electric dipole layer to adjust the crystal growth of perovskite films and charge behavior within devices. The better non-wetting surface of ZnO/PbS-TBAI ETLs improves the crystallization of the perovskite films by suppressing heterogeneous nucleation. And the unique energy level alignment of ZnO/PbS-TBAI induced by tunable surface dipole moment of TBAI boosted hetero-interface charge extraction of PSCs. Consequently, the optimized ZnO/PbS-TBAI based PSCs exhibits the power conversion efficiency (PCE) of 20.53 %, which is the champion PCE of ZnO PSCs with MAPbI 3 as the absorption layer. Stability tests also proved that the PCE of ZnO/PbS-TBAI based PSCs remains more than 86 % after exposure to 40 % humidity for 30 days, which is much more superior to that of control device. We firstly used iodination PbS QD films in this work to achieve higher photovoltaic performance in ZnO based PSCs, which prompts the further application of QDs materials within optoelectronic devices. [ABSTRACT FROM AUTHOR]