Unveiling Property of Hydrolysis-Derived DMAPbI3 for Perovskite Devices: Composition Engineering, Defect Mitigation, and Stability Optimization

Abstract

Summary Additive engineering has become increasingly important for making high-quality perovskite solar cells (PSCs), with a recent example involving acid during fabrication of cesium-based perovskites. Lately, it has been suggested that this process would introduce dimethylammonium ((CH 3 ) 2 NH 2 + , DMA + ) through hydrolysis of the organic solvent. However, material composition of the hydrolyzed product and its effect on the device performance remain to be understood. Here, we present an in-depth investigation of the hydrolysis-derived material (i.e., DMAPbI 3 ) and detailed analysis of its role in producing high-quality PSCs. By varying the ratio of CsI/DMAPbI 3 in the precursor, we achieve high-quality Cs x DMA 1-x PbI 3 perovskite films with uniform morphology, low density of trap states, and good stability, leading to optimized power conversion efficiency up to 14.3%, with over 85% of the initial efficiency retained after ∼20 days in air without encapsulation. Our findings offer new insights into producing high-quality Cs-based perovskite materials.

Unveiling the Effects of Hydrolysis‐Derived DMAI/DMAPbIx Intermediate Compound on the Performance of CsPbI3 Solar Cells

“…Here, HI acts with PbI 2 containing DMF to remove H 2 O, PbO, and PbO 2 in PbI 2 and also eventually form dimethylammonium (DMA + ) group . Similarly, Liu and coworkers reported hydrolysis‐derived materials (i.e., DMAPbI 3 ) and analyzed its role in producing high‐quality PSCs in detail by changing the ratio of CsI/DMAPbI 3 in the precursor . However, Zhao and coworkers established that an optimized annealing process could remove all organic species.…”

Suppression of phase transitions and glass phase signatures in mixed cation halide perovskites

“…Recently, dimethylammonium (DMA, (CH 3 ) 2 NH 2 + ) has been proposed as another alternative A-site cation in these compounds [28][29][30][31] . Several investigations reveal that during certain synthesis procedures relatively high quantities of DMA may be unintentionally mixed into the structures of MAPbI 3 and CsPbI 3 [32][33][34] .…”

Ruddlesden–Popper 2D Component to Stabilize γ‐CsPbI3 Perovskite Phase for Stable and Efficient Photovoltaics

“…growth of the precursor film [22,23] or introduced intermediate phase [24][25][26] (small amount of dimethylammonium (DMA + ) cation is proved as alternative A site cation [27,28] ). Most recently, Zhao and co-workers reported a record PCE of α-CsPbI 3 PSCs over 17% with phenyltrimethylammonium bromide (PTABr) as surface passivation and β-CsPbI 3 PSCs over 18% by choline iodine treatment.…”