Quantum hybridization negative differential resistance from non-toxic halide perovskite nanowire heterojunctions and its strain control

Abstract

While low-dimensional organometal halide perovskites are expected to open up new opportunities for a diverse range of device applications, like in their bulk counterparts, the toxicity of Pb-based halide perovskite materials is a significant concern that hinders their practical use. We recently predicted that lead triiodide (PbI3) columns derived from trimethylsulfonium (TMS) lead triiodide (CH3)3SPbI3 (TMSPbI3) by stripping off TMS ligands should be semimetallic, and additionally ultrahigh negative differential resistance (NDR) can arise from the heterojunction composed of a TMSPbI3 channel sandwiched by PbI3 electrodes. Herein, we computationally explore whether similar material and device characteristics can be obtained from other one-dimensional halide perovskites based on non-Pb metal elements, and in doing so deepen the understanding of their mechanistic origins. First, scanning through several candidate metal halide inorganic frameworks as well as their parental form halide perovskites, we find that the germanium triiodide (GeI3) column also assumes a semimetallic character by avoiding the Peierls distortion. Next, adopting the bundled nanowire GeI3-TMSGeI3-GeI3 junction configuration, we obtain a drastically high peak current density and ultrahigh NDR at room temperature. Furthermore, the robustness and controllability of NDR signals from GeI3-TMSGeI3-GeI3 devices under strain are revealed, establishing its potential for flexible electronics applications. It will be emphasized that, despite the performance metrics notably enhanced over those from the TMSPbI3 case, these device characteristics still arise from the identical quantum hybridization NDR mechanism.

Flexible kesterite thin-film solar cells under stress

“…In the convex bending state, the Fermi level of Na-doped CZTSSe located lower than in Na-undoped CZTSSe resulted in larger quasi-Fermi level splitting. Deformation in the electronic structure of absorber materials can affect the band alignment at the interface and thus transport of charge carriers 35,36 . The Tauc plot, work function, and VBM variations of the CZTSSe samples with the NaF layer inserted in the various positions are presented in Supporting Information (Supplementary Figs.…”

Flexible kesterite thin-film solar cells under stress

“…Deformation in the electronic structure of absorber materials can affect the band alignment at the interface and thus transport of charge carriers. 35,36 The Tauc plot, work function, and VBM variations of the CZTSSe samples with the NaF layer inserted in the various positions are presented in Supporting Information (Fig. S2, S3).…”

Synergistic Effect of Hybrid CdSe Nanobelt/PbI2 Flake Heterojunction Toward Drastic Performance Flexible Photodetectors

“…In order to overcome the constraints of electronics relying on 2D PbI 2 material, mixed-dimensional heterostructures, as a possible solution for future multifunctional platforms, are assumed to be a convenient and effective approach. − Compared to the individual material, a mixed-dimensional heterostructure not only manifests the intrinsic properties of both individual components, as well as displays the extra desirable characteristics as a result of interplay at each component’s interface. − Low cost CdSe, as an important photoelectric chalcogenide of the II–VI group with a direct bandgap of ∼1.74 eV at room temperature, is widely explored in optoelectronics due to its excellent optical and electrical characteristics. − Among other morphologies of CdSe, a distinct 1D nanobelt like morphology with a rectangular shape at the edges has been widely studied in photodetectors. ,− Thus, the present study integrates the distinct properties of the aforementioned sensing materials to fabricate a well performing 1D/2D hybrid heterojunction photodetector. To date, there is no available approach for the fabrication of broadband flexible photodetectors utilizing a single crystalline CdSe nanobelt/2D PbI 2 flake hybrid heterojunction on a cost-effective flexible polyimide tape-based substrate.…”