Rational Core–Shell Design of Open Air Low Temperature In Situ Processable CsPbI₃ Quasi‐Nanocrystals for Stabilized p‐i‐n Solar Cells

Abstract

As a promising alternative, inorganic perovskite nanocrystals allow reinforced stability of photovoltaic device. Unfortunately, directly assembling these nanocrystals into film is uncontrollable. Instead, in situ assembling technology under low temperature in open air is attractive but limited due to the tendency of nonperovskite transition. The adverse shell ligands and unstable core lattices are known as the fundamental problems. In order to address this issue, here proposed is a rational core–shell design: 1) with respect to ligands, a new one, 4‐fluorophenethylammonium iodide, is used to enhance bonding force and charge coupling between ligands and nanocrystals; 2) with respect to lattices, a novel compound H2PbI4 is employed to assist divalent ion (Mn2+) doping into perovskite lattices. By low temperature in situ processing CsPbI3 quasi‐nanocrystal film, the highest power conversion efficiency of 13.4% for p‐i‐n solar cells is achieved, which retains 92% after 500 h in ambient air. The current study underlines the significance of rational hierarchical design of inorganic perovskite nanocrystals, especially for low temperature in situ processable electronic devices.

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

“…In our early work, we also believed that the HPbI 3 replaces PbI 2 leading to the formation of a stabilized distorted black phase . Most recently, Xi et al increased HI amount to fabricate another new compound H 2 PbI 4 to fabricate stabilized CsPbI 3 PSCs …”

The Role of Dimethylammonium Iodide in CsPbI3 Perovskite Fabrication: Additive or Dopant?

“…[13] Consequently,t he precursor of "HPbI 3 "a nd "HPbI x "h ave been developed to improve the deposition of black phase CsPbI 3 perovskite. [14,[20][21][22][23][24][25] Recently, some studies have revealed that the acid would react with the dimethylformamide (DMF) to form formic acid and dimethylamine (CH 3 ) 2 NH:DMA). [26,27] Therefore,the HI additive would induce the formation of DMAI, the previously reported "HI" additive and "HPbI 3 "s hould be DMAI and DMAPbI 3 .H ence,t he role of DMAI in the fabrication of CsPbI 3 should be clarified.…”

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

“…[45] And most recently, Grätzel and coworkers also updated the PCE of 3D/2D organic-inorganic hybrid PSCs over 22% with water-and heat-resistant operationally stable. [49] 2) 2D structure: Jin and co-workers used long-chain ammonium as surface capping ligands resulting in the stabilized 2D structure based β-CsPbI 3 black phase. 1) 0D quantum dots (QDs): Reducing the crystal size will led to more surface to accommodate organic group, which makes the α-CsPbI 3 more stable.…”