Large-Area Photonic Membranes Achieving Uniform and Strong Enhancement of Photoluminescence and Second-Harmonic Generation in Monolayer WSe2
Journal
Small Methods
Journal Volume
10
Journal Issue
4
Start Page
e01693
ISSN
23669608
Date Issued
2026-02-23
Author(s)
Hsieh, Fong-Liang
Deng, Chih-Zong
Huang, Shao-Ku
Liu, Tsung-Hsin
Chen, Mu-Hsin
Chiang, Chun-Hao
Lee, Che-Lun
Lai, Man-Hong
Fu, Jui-Han
Tung, Vincent
Chang, Yu-Ming
Ho, Ya-Lun
Abstract
Two-dimensional (2D) transition metal dichalcogenides exhibit strong excitonic responses, direct bandgaps, and remarkable nonlinear optical properties, making them highly attractive for integrated photonic, optoelectronic, and quantum applications. Here, we present a large-area freestanding membrane photonic platform that achieves exceptional enhancement of light–matter interactions in monolayer WSe2 via quasi-bound states in the continuum (quasi-BICs). The freestanding architecture effectively suppresses radiative losses and supports high-Q optical resonances, leading to enhanced light–matter interactions. This results in significant photoluminescence emission and second-harmonic generation (SHG) enhancement factors of 1158 and 378, respectively, with spatial uniformity sustained across a 450 × 450 µm2 area. This uniform SHG enhancement further enables polarization-resolved mapping of crystal orientation and grain boundaries, offering a practical method for large-area structural characterization of 2D materials. Moreover, femtosecond-pumped SHG spectra reveal multiple narrowband peaks originating from distinct quasi-BIC modes—providing direct spectral evidence of resonantly enhanced nonlinear coupling. The combined attributes of strong optical enhancement, spectral selectivity, and wafer-scale compatibility establish this platform as a scalable interface for 2D semiconductor integration in next-generation optoelectronic, nonlinear, and quantum photonic technologies.
Subjects
bound states in the continuum
membrane
PL enhancement
second-harmonic generation
transition metal dichalcogenides
WSe2
Publisher
John Wiley and Sons Inc
Type
journal article