The extensive application of GaSe in optoelectronic devices has generated great enthusiasm for the study of their fundamental properties. Despite its high quantum yield and superb nonlinearity, the intrinsic out-of-plane transition dipole of excitons in GaSe leads mainly to in-plane photoluminescence (PL) emission, which results in poor detection efficiency normal to the sample surface. Here, we demonstrate a practical strategy for boosting and modulating the PL of GaSe by transferring it onto dielectric linear Bragg gratings (LBGs), achieving a significant 42-fold enhancement in PL at room temperature. Furthermore, the use of the LBG results in strong linear polarization of the original isotropic PL emission. In addition, temperature-dependent experiments indicate that the LBG results in maximum modulation of PL at 605 nm, an up to 150-fold increase. Through this work, we provide a facile method to enhance the exciton recombination and light outcoupling efficiency of GaSe, which can be further applied to other van der Waals layered materials with out-of-plane optical dipole transition for enhanced optoelectronic device performance.

Post-transition metal chalcogenides (PTMCs), which are composed of group IIIA (Ga, In) and group VI chalcogen atoms (S, Se, and Te), have emerged as an advanced family of 2D layered materials. As a typical representative of these materials, gallium selenide (GaSe) has been extensively studied due to its superior nonlinear optical characteristics, excellent photo response, high carrier mobility, and so on.1–61. K. S. Novoselov, A. Mishchenko, A. Carvalho, and A. H. Castro Neto, Science 353(6298), aac9439 (2016). https://doi.org/10.1126/science.aac94392. K. F. Mak and J. Shan, Nat. Photonics 10(4), 216 (2016). https://doi.org/10.1038/nphoton.2015.2823. X. Li, H. Liu, C. Ke, W. Tang, M. Liu, F. Huang, Y. Wu, Z. Wu, and J. Kang, Laser Photonics Rev. 15(12), 2100322 (2021). https://doi.org/10.1002/lpor.2021003224. A. Bergeron, J. Ibrahim, R. Leonelli, and S. Francoeur, Appl. Phys. Lett. 110(24), 241901 (2017). https://doi.org/10.1063/1.49861895. H. Arora and A. Erbe, InfoMat 3(6), 662 (2021). https://doi.org/10.1002/inf2.121606. S. Ahmed, P. K. Cheng, J. Qiao, W. Gao, A. M. Saleque, M. N. Al Subri Ivan, T. Wang, T. I. Alam, S. U. Hani, and Z. L. Guo, ACS Nano 16(8), 12390 (2022). https://doi.org/10.1021/acsnano.2c03566 These features make it a promising material for nano-optoelectronic devices such as photodetectors,7–97. Z. Zou, J. Liang, X. Zhang, C. Ma, P. Xu, X. Yang, Z. Zeng, X. Sun, C. Zhu, and D. Liang, ACS Nano 15(6), 10039 (2021). https://doi.org/10.1021/acsnano.1c016438. X. Wu, Y. Liu, M. Li, W. Guo, T. Ou, C. Xiao, J. Yao, Y. Yu, Y. Zheng, and Y. Wang, ACS Appl. Nano Mater. 5, 8012 (2022). https://doi.org/10.1021/acsanm.2c011099. Y. Niu, J. Zeng, X. Liu, J. Li, Q. Wang, H. Li, N. Frans de Rooij, Y. Wang, and G. Zhou, Adv. Sci. 8(14), 2100472 (2021). https://doi.org/10.1002/advs.202100472 lasers,1010. K. R. Allakhverdiev, M. Ö. Yetis, S. Özbek, T. K. Baykara, and E. Y. Salaev, Laser Phys. 19(5), 1092 (2009). https://doi.org/10.1134/S1054660X09050375 and single photon sources.1111. P. Tonndorf, S. Schwarz, J. Kern, I. Niehues, O. D. Pozo-Zamudio, A. I. Dmitriev, A. P. Bakhtinov, D. N. Borisenko, N. N. Kolesnikov, and A. I. Tartakovskii, 2D Mater. 4(2), 021010 (2017). https://doi.org/10.1088/2053-1583/aa525b However, the band edge emission from GaSe involves an out-of-plane transition dipole,12,1312. M. Brotons-Gisbert, R. Proux, R. Picard, D. Andres-Penares, A. Branny, A. Molina-Sánchez, J. F. Sánchez-Royo, and B. D. Gerardot, Nat. Commun. 10(1), 3913 (2019). https://doi.org/10.1038/s41467-019-11920-413. Y. Tang, W. Xie, K. C. Mandal, J. A. McGuire, and C. W. Lai, Phys. Rev. Appl. 4(3), 034008 (2015). https://doi.org/10.1103/PhysRevApplied.4.034008 which yields majority of photoluminescence (PL) emission along the sample plane. This limits the optical detection efficiency perpendicular to the sample surface and hinders the optical performance of both light-emitting and detection devices. Therefore, there is a requirement for a framework to enhance and modulate the optical response of GaSe to meet the needs of future optoelectronic applications.Recently, some techniques to improve the optical emission of PTMCs have been proposed, including using strain and plasmonic nanostructures.14–1714. W. Wan, J. Yin, Y. Wu, X. Zheng, W. Yang, H. Wang, J. Zhou, J. Chen, Z. Wu, and X. Li, ACS Appl. Mater. Interfaces 11(21), 19631 (2019). https://doi.org/10.1021/acsami.9b0388015. J. Zhou, Y. Wu, H. Wang, Z. Wu, X. Li, W. Yang, C. Ke, S. Lu, C. Zhang, and J. Kang, Nanoscale 12(6), 4069 (2020). https://doi.org/10.1039/C9NR09057F16. N. Liu, X. Yang, Z. Zhu, F. Chen, Y. Zhou, J. Xu, and K. Liu, Nanoscale 14(1), 49 (2022). https://doi.org/10.1039/D1NR06216F17. S.-Y. Ding, J. Yi, J.-F. Li, B. Ren, D.-Y. Wu, R. Panneerselvam, and Z.-Q. Tian, Nat. Rev. Mater. 1(6), 16021 (2016). https://doi.org/10.1038/natrevmats.2016.21 However, these methods require complicated fabrication processes, which may hinder optoelectronic applications of PTMCs. Therefore, a universal method is required to overcome these problems and improve the optical response of PTMCs devices. As efficient approaches, photonic waveguides,1616. N. Liu, X. Yang, Z. Zhu, F. Chen, Y. Zhou, J. Xu, and K. Liu, Nanoscale 14(1), 49 (2022). https://doi.org/10.1039/D1NR06216F optical fibers,1818. J. Chen, J. Tan, G. Wu, X. Zhang, F. Xu, and Y. Lu, Light: Sci. Appl. 8(1), 8 (2019). https://doi.org/10.1038/s41377-018-0115-9 plasmonic excitonic structures,1919. J. Shi, X. Wu, K. Wu, S. Zhang, X. Sui, W. Du, S. Yue, Y. Liang, C. Jiang, and Z. Wang, ACS Nano 16(9), 13933 (2022). https://doi.org/10.1021/acsnano.2c03033 and micro-cavities2020. J. Shi, J. Zhu, X. Wu, B. Zheng, J. Chen, X. Sui, S. Zhang, J. Shi, W. Du, and Y. Zhong, Adv. Opt. Mater. 8(23), 2001147 (2020). https://doi.org/10.1002/adom.202001147 have been previously proven to enhance the optical response from transition-metal dichalcogenides (TMDCs). In this field, linear Bragg gratings (LBGs), which are characterized by small mode size and efficient photon extraction over a wide bandwidth, have been widely applied by researchers.21–2321. J. Shi, W.‐Y. Liang, S. S. Raja, Y. Sang, X.‐Q. Zhang, C.‐A. Chen, Y. Wang, X. Yang, Y.‐H. Lee, and H. Ahn, Laser Photonics Rev. 12(10), 1800188 (2018). https://doi.org/10.1002/lpor.20180018822. M. Y. Su and R. P. Mirin, Appl. Phys. Lett. 89(3), 033105 (2006). https://doi.org/10.1063/1.222234523. C.-Y. Wang, H.-Y. Chen, L. Sun, W.-L. Chen, Y.-M. Chang, H. Ahn, X. Li, and S. Gwo, Nat. Commun. 6(1), 7734 (2015). https://doi.org/10.1038/ncomms8734 For instance, Chen et al. found that the linear and nonlinear optical responses of WS2 were enhanced by 34 and 5 times through coupling with 2D nanogroove gratings.2424. B. Chen, Z. He, Z.-J. Liu, Y.-K. Wang, Y.-N. Gao, I. Aharonovich, Z.-Q. Xu, and J. Liu, Nanophotonics 9(8), 2587 (2020). https://doi.org/10.1515/nanoph-2020-0143 Lien et al. demonstrated that the LBGs showed unique appeal and promise for integration with 2D materials.2525. M. R. Lien, N. Wang, J. Wu, A. Soibel, S. D. Gunapala, H. Wang, and M. L. Povinelli, Nano Lett. 22(21), 8704 (2022). https://doi.org/10.1021/acs.nanolett.2c03469 Thereupon, the use of LBGs is thus expected to be a feasible approach to modulating the optical performance of PTMCs.

In this work, we designed LBGs consisting of 2D nanogrooves with subwavelength pitch on high-refractive Si plates, which can confine the electric field to a limited space and promote the interaction between light and material. As predicted, the GaSe PL was significantly enhanced about 42-fold under the resonance of LBGs at 295 K. Furthermore, by interacting with the LBGs, the out-coupled PL emission of GaSe exhibits linear polarization along the grating direction. In addition, temperature-dependent experiments revealed that the best matching of the resonance peak matching with the LBGs was located at 605 nm, and the maximum PL augmentation was up to 150 times. The approach described herein provides a practical method for improving the exciton recombination and photocoupling efficiency of GaSe, and it can also be applied to other layered materials with out-of-plane transition dipole to enhance the optical performance of optoelectronic devices.

Figure 1(a) shows that a single layer of GaSe consists of a covalently bonded Se–Ga–Ga–Se structure, and the layers are joined by van der Waals forces. The ɛ-GaSe used in this work comprises a hexagonal close-packed lattice with an A–B–A stacking pattern. As the layer numbers increase beyond seven, GaSe transforms from an indirect to a quasi-direct bandgap.26–2826. S. Nagel, A. Baldereschi, and K. Maschke, J. Phys. C: Solid State Phys. 12(9), 1625 (1979). https://doi.org/10.1088/0022-3719/12/9/00627. L. Ghalouci, B. Benbahi, S. Hiadsi, B. Abidri, G. Vergoten, and F. Ghalouci, Comp. Mater. Sci. 67, 73 (2013). https://doi.org/10.1016/j.commatsci.2012.08.03428. X. Li, M.-W. Lin, A. A. Puretzky, J. C. Idrobo, C. Ma, M. Chi, M. Yoon, C. M. Rouleau, I. I. Kravchenko, and D. B. Geohegan, Sci. Rep. 4(1), 5497 (2014). https://doi.org/10.1038/srep05497 GaSe blocks with about 180 nm thickness were thus selected for further fabrication due to their good optical response and stability. We used an optical microscope to estimate the thickness of the GaSe bulks samples, as GaSe pigments are thickness-dependent.2929. W. Zhang, Q. Zhao, S. Puebla, T. Wang, R. Frisenda, and A. Castellanos-Gomez, Mater. Today Adv. 10, 100143 (2021). https://doi.org/10.1016/j.mtadv.2021.100143 Figure 1(b) shows an optical image of target thickness, and the red dashed line depicts the thickness of 180 nm, as measured by atomic force microscopy [Fig. 1(c)]. Each GaSe flake used in this work had a thickness very close to our target of 180 nm.Figure S1 shows a dark field image of LBGs. It can be clearly seen that the nanogroove grating is optically dark in the center and brighter in the boundary because incident light can barely escape from the grating structure except at the edges. A PL spectrum of the bulk GaSe is shown in Fig. 1(d), indicating that the center wavelength is 621.4 nm. The Raman spectrum in Fig. 1(e) shows three typical vibration modes of GaSe, A1′(1), E′, and  A1′(2), positioned at around 128, 206, and 302 cm−1, respectively, aligned with the previously reported results.30–3230. M. Rahaman, M. Bejani, G. Salvan, S. A. Lopez-Rivera, O. Pulci, F. Bechstedt, and D. R. T. Zahn, Semicond. Sci. Technol. 33(12), 125008 (2018). https://doi.org/10.1088/1361-6641/aae4c731. S. Y. Lim, J.-U. Lee, J. H. Kim, L. Liang, X. Kong, T. T. H. Nguyen, Z. Lee, S. Cho, and H. Cheong, Nanoscale 12(15), 8563 (2020). https://doi.org/10.1039/D0NR00165A32. S. Lei, L. Ge, Z. Liu, S. Najmaei, G. Shi, G. You, J. Lou, R. Vajtai, and P. M. Ajayan, Nano Lett. 13(6), 2777 (2013). https://doi.org/10.1021/nl4010089 No obvious spectral change or other vibration modes are observed, indicating the high-quality of the GaSe layers crystal.Despite the high quantum efficiency of GaSe, the in-plane photon propagation along the GaSe surface may result in a deficiency in the optical response of traditional optical systems. A series of LBGs were thus designed to improve the collection efficiency by redirecting the horizontally propagated signal to vertical scattering. Si (n = 3.97) was selected for the preparation of these LBGs because of its homogeneous structure.3333. D. E. Aspnes and A. A. Studna, Phys. Rev. B 27(2), 985 (1983). https://doi.org/10.1103/PhysRevB.27.985 A focused ion beam was used to fabricate the V-shaped nanogrooves with a spacing of 200 nm. A diagram of the hybrid GaSe–Si LBGs structure is shown in Fig. 2(a). This illustrates the vertical scattering of horizontally propagating photons by the GaSe–Si hybrid grating structure, which increases the GaSe PL intensity. The resonator consists of dozens of parallel sub micrometer lines used as waveguides. The V-shaped channels operate under second-order Bragg conditions and provide reflection feedback to the cavity, leading to a near-vertical upward scattering of photons. With the Si Bragg gratings, we can simultaneously enhance the PL and explore the Bragg effect on improving PL collection efficiency.Since the geometric parameters of LBGs significantly influence their resonance peak,1414. W. Wan, J. Yin, Y. Wu, X. Zheng, W. Yang, H. Wang, J. Zhou, J. Chen, Z. Wu, and X. Li, ACS Appl. Mater. Interfaces 11(21), 19631 (2019). https://doi.org/10.1021/acsami.9b03880 the nanostructure needs to be designed to achieve an ideal match between their resonance peak and the GaSe PL emission. Previous studies were carried out and found that is determined by its structure parameters that the resonance wavelength of the linear grating is determined by its structure parameters,2121. J. Shi, W.‐Y. Liang, S. S. Raja, Y. Sang, X.‐Q. Zhang, C.‐A. Chen, Y. Wang, X. Yang, Y.‐H. Lee, and H. Ahn, Laser Photonics Rev. 12(10), 1800188 (2018). https://doi.org/10.1002/lpor.201800188 including grating length L, depth D, and periodicity P. The in-plane and cross-sectional scanning electron microscopy of typical LBGs are shown in Fig. 2(b). We adjusted the resonance wavelength to match the GaSe PL emission by modifying the periodicity parameters of the Si pitch, as shown in Fig. 2(c). The simulation results of reflection spectra from Si gratings with different periods were obtained with constant parameters of L (70 nm) and D (67 nm) using the finite-different time-domain (FDTD) method. Each structure had 31 unit cells. Focusing on the reflection spectrum of each curve, the resonance center wavelengths were observed locating at 608, 620, and 632 nm when P = 200, 210, and 220 nm, respectively. A distinct resonance absorption at 620 nm with a broadband reflection of up to 0.8 is shown when the period is 210 nm. The LBG with P = 210 nm was found to have a resonance peak at 620 nm. This matches the fluorescence resonance wavelength of GaSe, making it an ideal structure for the vertical scattering of GaSe photons into free space when the second-order Bragg diffraction condition is met.To verify the enhancement effect of the gratings, we fabricated the three different gratings and then transferred GaSe to the micro–nanostructures with the full dry transfer technique. Figures 3(a)–3(c) display the SEM images of linear gratings with periods of 200, 210, and 220 nm, respectively. To evaluate the LBG-enhanced optical response of GaSe under these situations, we measured the PL spectra of pristine GaSe and the GaSe/Si samples. The gratings with various periods were applied to investigate the second-order Bragg effect and the best-fit parameters. As noted, the emission enhancement will be at a maximum when the response wavelength of the Bragg grating is optimally matched to the emission wavelength of the material. At this point, the Bragg second-order diffraction condition is met: where neff is the effective refractive index, Λ is the period of the gratings, m is the diffraction order, and λB is the resonance wavelength of the Bragg gratings.34,3534. M. Jäckle, H. Linnenbank, M. Hentschel, M. Saliba, S. G. Tikhodeev, and H. Giessen, Opt. Mater. Express 9(5), 2006 (2019). https://doi.org/10.1364/OME.9.00200635. N. M. H. Duong, Z.-Q. Xu, M. Kianinia, R. Su, Z. Liu, S. Kim, C. Bradac, T. T. Tran, Y. Wan, and L.-J. Li, ACS Photonics 5(10), 3950 (2018). https://doi.org/10.1021/acsphotonics.8b00865 Figures 3(d)–3(f) displayed the PL mappings of the coupled structures. The three mappings show a bright yellow rectangle in the center with dark surroundings, indicating that the PL of the GaSe is enhanced through coupling with the Si LBG structures. Excellent uniformity can be seen in these mappings, and there is a dark border in each case because the dispersion of the photons in the border is more significant than in the center. Due to the incompleteness of the boundary grating structure, the Bragg diffraction condition in the boundaries cannot be perfectly satisfied. As predicted by the simulation in Fig. 2(c), the optimal grating design, in resonance with PL emission of GaSe, has a period of P = 210 nm.To quantitatively characterize the enhancement factor (EF) in each case, we calculated the average EF by comparing the fluorescence of GaSe on a flat Si substrate and the fluorescence of GaSe coupled with a Si LBG. This is calculated as where I and ILBG are the PL intensities from the pristine GaSe and the GaSe/Si gratings structure, respectively. As plotted in Figs. 3(g)–3(i), the calculated EFs are 27, 42, and 30 when the LBGs with periods of 200, 210, and 220 nm, respectively. The coupled PL is slightly redshifted compared to pristine GaSe, which is attributed to the strain effect of the material transferred to the grating.1515. J. Zhou, Y. Wu, H. Wang, Z. Wu, X. Li, W. Yang, C. Ke, S. Lu, C. Zhang, and J. Kang, Nanoscale 12(6), 4069 (2020). https://doi.org/10.1039/C9NR09057FIn light of these results, we chose a grating period of 210 nm for the subsequent experiments. Figure S2 shows the Raman variations from GaSe after coupling with the LBGs. The spectrum exhibits a slight enhancement, which may arise from the strain effect of binding to the grating.1515. J. Zhou, Y. Wu, H. Wang, Z. Wu, X. Li, W. Yang, C. Ke, S. Lu, C. Zhang, and J. Kang, Nanoscale 12(6), 4069 (2020). https://doi.org/10.1039/C9NR09057F We conducted comparison experiments with WS2 and GaSe on the gratings. As seen in Fig. S3, the enhancement factor of WS2 on the nanogrooves is about 4, while 42-fold enhancement was obtained for GaSe under the same conditions. This can be attributed to different grating coupling efficiency between the out-of-plane and in-plane polarization dipole, while WS2 has in-plane dipole orientation and has an emission close to the peak of GaSe. Furthermore, we tested the WS2 time-resolved fluorescence spectra before and after coupling, and we observed a shortened lifetime when coupled to the gratings (P = 210 nm), as illustrated in Fig. S4. Combined with the enhancement of the PL, we could infer that there exists the Purcell effect between the material and structures.Using the optimal LBG, we further explore the GaSe PL polarization modulation that resulted from coupling with the grating. During the measurements, the incident light and sample direction were fixed. The polarization direction of the collection linear polarizer (LP) was also fixed to eliminate the different responses for s-polarized and p-polarized lights of spectrometer. The electric-field polarization was tuned by rotating a half-wave plate placed in front of the LP, allowing examination of the full range of possible polarizations. Figures 3(j) and 3(k) show polar plots of the collected PL intensity as a function of the angle between the photon-propagation direction and the grating direction. The PL plot shown in Fig. 3(j) is circular, indicating that the PL of pristine GaSe is isotropic. In contrast, Fig. 3(k) shows that the GaSe coupled to the grating has twofold symmetry. It can thus be concluded that the polarization of the GaSe PL was modulated based on the orientation of the grating.To maximize the coupling efficiency, we altered the PL and the resonance mode of the LBGs by varying the temperature. Figure 4(a) shows the normalized temperature-dependent PL spectra of GaSe on LBG with a period of 210 nm. The PL of GaSe is blue-shifted with decreasing temperature, and its spectrum splits into bound and free excitons since 120 K.3636. C. Wei, X. Chen, D. Li, H. Su, H. He, and J.-F. Dai, Sci. Rep. 6(1), 33890 (2016). https://doi.org/10.1038/srep33890 We fitted the free and bound state exciton PL at different temperatures and calculated the enhancement factors, as plotted in Fig. 4(b). The black dots represent the free excitons' enhancement under different center wavelengths, and the red dots denote those of the bound excitons. With the blue shift of the wavelength, the enhancement factors of both bound and free excitons show non-monotonic features, in which the maximum enhancement are located at 605 nm. The response wavelength of the gratings varies with temperature, and this is caused by the changing dielectric constant.2424. B. Chen, Z. He, Z.-J. Liu, Y.-K. Wang, Y.-N. Gao, I. Aharonovich, Z.-Q. Xu, and J. Liu, Nanophotonics 9(8), 2587 (2020). https://doi.org/10.1515/nanoph-2020-0143 Since this alteration brings the emission line into resonance with the cavity mode, a 150-fold PL enhancement is acquired.The luminescence intensity is significantly enhanced after decorating with periodic linear gratings, indicating an increase in the vertical light emission and local light field through Bragg diffraction and the Purcell effect. Time-resolved luminescence spectra for the on and off-grating GaSe using a 400 nm femtosecond pulsed laser excitation at 80 K were obtained, and representative spectra are shown in Fig. 4(c). These plots indicate that the fitted lifetimes of the GaSe on-and off-grating are identified as 19.28 and 34.72 ps, respectively. After performing several measurements on the coupled and uncoupled parts of the same GaSe and averaging the data, we obtained a Purcell factor of ∼1.6 for GaSe emission when coupled to the grating structure.

In summary, using simulations and experiments, we have illustrated the enhancement of GaSe PL by integration with a Si LBG structure. A 42-fold enhancement was obtained at 295 K. This enhancement is attributed to second-order Bragg second order diffraction and the enhanced emission rate (Purcell effect). The polarization can be modulated by using a linear grating with high polarization extinction which is dependent on the grating's orientation. In addition, the observation of temperature-dependent PL revealed the enhancement mechanism and provided an operational strategy that can be applied to hybrid optical systems. Our results manifest that a structure consisting of PTMCs-patterned surfaces can simultaneously enhance and modulate the optical signal of materials. This approach is promising for improving the performance improvement of van der Waals layered materials with an out-of-plane optical dipole transition.

See the supplementary material for details, including structures and sample preparation, the dark-field image of the system, Raman spectra, the comparison enhancement of WS2 and GaSe hybrid structure, and the time-resolved PL of WS2 with and without gratings.

The authors are grateful to the National Natural Science Foundation of China (Nos. 62175061, 52172140, and 52221001), the Natural Science Foundation of Hunan Province (No. 2022JJ30167), the Outstanding Scholarship Program of Hunan Province (No. 2021JJ10021), and the China Postdoctoral Science Foundation (Nos. BX20220104, 2022M720046, and 2022TQ0100).

Conflict of Interest

The authors have no conflicts to disclose.

Author Contributions

Q.J. and Y.L. contributed equally to this work.

Qi Jiang: Conceptualization (equal); Data curation (equal); Formal analysis (equal); Investigation (equal); Methodology (equal); Resources (equal); Software (equal); Supervision (equal); Validation (equal); Visualization (equal); Writing – original draft (equal); Writing – review & editing (equal). Xiao Yi: Formal analysis (equal); Investigation (equal); Resources (equal). Xin Yang: Data curation (equal); Funding acquisition (equal); Methodology (equal). Shula Chen: Conceptualization (equal); Data curation (equal); Formal analysis (equal); Funding acquisition (equal); Project administration (equal); Supervision (equal); Writing – original draft (equal); Writing – review & editing (equal). Anlian Pan: Conceptualization (lead); Funding acquisition (lead); Resources (supporting); Supervision (supporting); Validation (lead). Yong Liu: Data curation (equal); Formal analysis (equal); Investigation (equal). Ziyu Luo: Data curation (supporting); Formal analysis (supporting); Investigation (supporting). Ronghuan Sun: Formal analysis (supporting); Investigation (supporting); Resources (supporting). Ying Chen: Data curation (supporting); Investigation (supporting); Software (supporting). Yunfei Xie: Data curation (equal); Formal analysis (equal). Qin Shuai: Data curation (supporting); Formal analysis (supporting); Resources (supporting). Pan Xu: Data curation (equal); Formal analysis (equal); Methodology (equal). Quanlong Zhang: Data curation (supporting); Formal analysis (supporting).

The data that support the findings of this study are available from the corresponding authors upon reasonable request.

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