@article{Wang2026, 
author = {Yuying Wang and Yu Wang and Qichao Xue and Guiying Li and Ying Li and Wentao Yang and Chenying Yang and Yuchuan Shao and Tao Liang},
title = {Two-dimensional nonlayered CuInSe2 flakes with in-plane polarization for self-powered broadband Schottky photodetectors},
year = {2026},
journal = {Nano Research},
volume = {19},
number = {8},
pages = {94908739},
keywords = {two-dimensional (2D) nonlayered materials, copper indium selenide, self-powered photodetection, in-plane polarization, Cu vacancies},
url = {https://www.sciopen.com/article/10.26599/NR.2026.94908739},
doi = {10.26599/NR.2026.94908739},
abstract = {Ultrathin nonlayered chalcopyrite semiconductors provide an unique platform for integrating strong light-matter interactions, asymmetric crystal fields, and intrinsic defect engineering into high-performance optoelectronic devices. However, the device implementation has been hindered by controlled materials synthesis and reliable contact engineering. Herein, we demonstrate a molecular sieve-assisted chemical vapor deposition (CVD) strategy for the bottom-up growth of highly-crystalline two-dimensional (2D) CuInSe2 flakes with well-defined (112) facet orientation and periodic Cu vacancy ordering. Comprehensive structural and spectroscopic characterizations reveal that the ordered cation sublattice breaks inversion symmetry, producing spontaneous in-plane polarization that can be electrically modulated via Cu+ ion migration. Coupled with a selected Au/CuInSe2 Schottky contact, the intrinsic p-type conduction of 2D CuInSe2 is verified, and the combined effects of polarization and junction fields enable efficient photocarrier separation and extraction under zero bias. The resulting self-powered photodetectors exhibit broadband operation across 450–1064 nm, with high responsivity of 0.6 A/W, detectivity of 2.97 × 1010 Jones, and external quantum efficiency of 119% under 637 nm illumination. Furthermore, the devices deliver a peak power conversion efficiency of 10.4% and a rapid photoresponse time of 85–103 ms. These results establish 2D chalcopyrite semiconductors as a versatile platform for next-generation energy-efficient optoelectronic technologies.}
}