Revealing the impact of phase transition on n = 1 2D perovskite photodetectors with intrinsically tunable narrowband detection
Author(s)
Type
Journal Article
Abstract
2D perovskites featuring a single layer of perovskite octahedra sandwiched between organic cations (n = 1) display narrow absorption due to their quantum-confined structure. They offer a compelling route to filter-free, narrowband photodetection compared with broadband 3D counterparts. While halide mixing provides spectral tunability, it introduces severe phase segregation and energetic disorder. Current understanding of this phenomenon is derived mainly from static material characterisation, leaving its dynamic impact in operational devices unexplored. Herein, we bridge this gap by integrating n = 1 (PEA)2PbBrxI4-x into photoconductors, achieving tunable response from 400 to 520 nm, and a maximum specific detectivity (D*) of 2.11 × 1011 Jones at an applied bias of 20 V. We reveal the existence of two different phases and the gradual transition based on halide compositions, studied how mixing halide drives phase segregation with density functional theory calculations. Although the chloride additive PEACl suppressed phase segregation in mixed halides, it introduced additional traps that reduced photocurrent. The additive enhanced the out-of-plane orientation, disrupting in-plane transport in photoconductors, but significantly improved performance in photodiodes. This work provides the first device-level insight into halide immiscibility in n = 1 2D-perovskites, revealing that overcoming the performance limitations in these systems requires balancing long-range structural order with short-range electronic disorder.
Date Issued
2026-05-27
Date Acceptance
2026-03-30
Citation
Small, 2026, 22 (30)
ISSN
1613-6810
Publisher
Wiley
Journal / Book Title
Small
Volume
22
Issue
30
Copyright Statement
© 2026 The Author(s). Small published by Wiley-VCH GmbH This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/41930742
Subjects
halide immiscibility
n = 1 2d perovskite
narrowband detection
photoconductors
photodetector
Publication Status
Published
Coverage Spatial
Germany
Article Number
e73312
Date Publish Online
2026-04-03