Improved phase stability of γ-CsPbI₃ perovskite nanocrystals using the interface effect using iodine modified graphene oxide

Abstract

The variation of the active element on rGO leads to the stress state change of γ-CsPbI3 NCs, improving their phase stability.

Metastable γ-CsPbI3 Perovskite Nanocrystals Created Using Aged Orthorhombic CsPbBr3

“…14,24 In this year, Zhang et al reported the photocatalytic property of γ-CsPbI 3 NCs and achieved the improvement of the stability of γ-CsPbI 3 NCs using iodinemodified graphene oxide. 16,25 Former reports have demonstrated that anions can be selected to control various properties. 26 For CsPbX 3 NCs, postsynthetic anion exchange reactions (AERs) have become one of the most popular tools to precisely control halide compositions.…”

“…Different from the δ-phase which has the isolated PbX 6 octahedra, CsPbI 3 perovskites have many structural polymorphs, including cubic (α-phase), tetragonal (β-phase), and orthorhombic structures (γ-phase). − Black perovskite phases (α-/β-/γ-phase) exhibit 3D connectivity of corner-sharing PbX 6 octahedra and similar optoelectronic properties. − The α-phase of CsPbI 3 is only stable at temperatures above 320 °C . While cooling to room temperature, they underwent a fast phase transition process to γ-CsPbI 3 perovskites .…”

“…Creutz et al suggested the possibility of widespread γ-CsPbI 3 NCs . Bertolotti proposed an original depiction of the structural defectiveness and confirmed γ-CsPbI 3 NCs using X-ray total scattering techniques and the Debye scattering equation. , In this year, Zhang et al reported the photocatalytic property of γ-CsPbI 3 NCs and achieved the improvement of the stability of γ-CsPbI 3 NCs using iodine-modified graphene oxide. , …”

Formation Mechanisms and Phase Stability of Solid-State Grown CsPbI3 Perovskites

“…( Figure 1 ). Increasing the synthesis duration, the luminescence started to become not uniform, and a strong emission appeared at around 715 nm, typical of black phases α and γ [ 25 , 33 , 34 ] ( Figure 4 b).…”

Perovskite Quantum Dot Solar Cells: An Overview of the Current Advances and Future Perspectives

“…Interestingly, two other less-known polymorphs with similar properties and optoelectronic interest also exist: β-CsPbI 3 (tetragonal) and γ-CsPbI 3 (orthorhombic). [86][87][88][89] However, these photoactive polymorphs are converted into an orthorhombic yellow polymorph (δ-CsPbI 3 , Pnma) for temperatures lower than 320 C. [22,55,82,90] To visualize them more easily, schemes of these structures are shown in Figure 2 based on atomic coordinates and crystal ionic radii from previous studies. [11,20,79,91] In this figure, TCO and ETM refer to the transparent conducting oxide and electron transporting material, respectively.…”