Deconvoluting Energy Transport Mechanisms in Metal Halide Perovskites Using CsPbBr3 Nanowires as a Model System. (24th March 2021)

• Record Type: Journal Article
• Authors: Oksenberg, Eitan; Fai, Calvin; Scheblykin, Ivan G.; Joselevich, Ernesto; Unger, Eva L.; Unold, Thomas; Hages, Charles; Merdasa, Aboma
• Is Part Of: Advanced functional materials. Volume 31:Number 22(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-03-24
• Subjects: carrier diffusion -- energy transport -- perovskite nanowires -- photoluminescence -- photon recycling; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202010704
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Understanding energy transport in metal halide perovskites is essential to effectively guide further optimization of materials and device designs. However, difficulties to disentangle charge carrier diffusion, photon recycling, and photon transport have led to contradicting reports and uncertainty regarding which mechanism dominates. In this study, monocrystalline CsPbBr3 nanowires serve as 1D model systems to help unravel the respective contribution of energy transport processes in metal‐halide perovskites. Spatially, temporally, and spectrally resolved photoluminescence (PL) microscopy reveals characteristic signatures of each transport mechanism from which a robust model describing the PL signal accounting for carrier diffusion, photon propagation, and photon recycling is developed. For the investigated CsPbBr3 nanowires, an ambipolar carrier mobility of μ = 35 cm 2 V −1 s −1 is determined, and is found that charge carrier diffusion dominates the energy transport process over photon recycling. Moreover, the general applicability of the developed model is demonstrated on different perovskite compounds by applying it to data provided in previous related reports, from which clarity is gained as to why conflicting reports exist. These findings, therefore, serve as a useful tool to assist future studies aimed at characterizing energy transport mechanisms in semiconductor nanowires using PL. Abstract : A detailed study on individual perovskite nanowires is conducted with the aim to characterize the different forms in which energy can be transported in these semiconductor materials. A model is developed, which can be used to assess the contribution of each transport process and determine which is dominant. Charge mobility is also readily determined by the model.