CsPbI₃/PbSe Heterostructured Nanocrystals for High-Efficiency Solar Cells

Abstract

Colloidal cesium lead iodide (CsPbI3) perovskite quantum dots (QDs) are promising materials for solar cells because of their suitable optical bandgap and the ease of solution-based processing into large-area films. Herein, we report a synthetic strategy to build up a colloidal CsPbI3/PbSe heterostructure, which not only improves the absorption of sunlight but also passivates the surface of perovskite QDs, which results in a lower trap density and prolonged exciton lifetimes. Moreover, the presence of the PbSe component modifies the electronic properties of the composite films, by changing the CsPbI3 QD film from n-type to more ambipolar behavior, thus helping to promote carrier separation and collection. These improvements result in high-performance CsPbI3/PbSe QD solar cells with a power conversion efficiency of 13.9% and improved storage stability against moisture, benefiting from the hydrophobic protective coating resulting from the presence of PbSe component.

Stability of Quantum Dot Solar Cells: A Matter of (Life)Time

“…CsPbI 3 /PbSe heterostructured QDs were directly synthesized in a colloidal phase using trioctylphosphine selenide as a Se source. [ 150 ] TEM and HRTEM images in Figure 10c,d show a central area marked by an interplanar distance of 0.62 nm, which was identified as CsPbI 3 QDs. The surface region in these images was identified as PbSe, with an interplanar distance of 0.3 nm associated with its (200) plane.…”

Halide Perovskite–Lead Chalcohalide Nanocrystal Heterostructures

“… 26 Many of these nano-heterostructures may find applications in various fields, such as solar cells, LEDs, and photocatalysis. 23 , 27 , 28 …”

Quantum Dots for Photovoltaics: A Tale of Two Materials

“…Judicious integration of these two types of QDs can also be an efficient route to further improve photovoltaic performance. [90] In this review, we present an overview of state-of-the-art PbX and PVK QD solar cells, with a focus on their similarities and differences in terms of fundamental photophysics, device structures, and photovoltaic performance. First, an in-depth understanding of basic properties is discussed to compare PbX and PVK QDs from perspectives of quantum confinement effects, bandgap tuning, defect tolerance, and MEG.…”

“…a) Progress in the PCE and the accumulated publication numbers of lead‐based QD solar cells since 2010. [ 88–148 ] The data of the number of publications is taken from Scopus ( www.scopus.com). b) Schematic diagram of the material structure of PbX (X = S, Se) (Reproduced with permission.…”