## 4 Conclusions  
In this study, a WL-VLC system based on white-light GaN-based \(\mu\)LEDs with green and red PQDs as color converters was proposed and demonstrated experimentally for both communication and illumination. The essential optical and electrical performances of monochromatic light from the InGaN-\(\mu\)LEDs, G-PQDs, and R-PQDs, as well as the white light, were studied. The corresponding communication and illumination performances were systematically investigated in detail. We achieved the maximum bandwidths of 162 MHz, 90 MHz, 64 MHz, and 57.5 MHz for InGaN-\(\mu\)LEDs, R-PQDs, G-PQDs, and white-light in our WL-VLC system, respectively. High-quality white light was generated which possessed CIE of (0.3327, 0.3114) and a correlated color temperature of 5474 K. It is worth noting that using R-PQDs and G-PQDs as color converters, the available CIE of (0.3327, 0.3114) is closer to the CIE of (0.33, 0.33) for standard white light, compared with that (0.27, 0.30) of white light using yellow PQDs as color converters in our previous study. These results shed new light on the potential of InGaN-\(\mu\)LEDs combined with PQDs for both high-speed VLC and high-efficiency SSL.  
The following are available online at [[https://www.mdpi.com/article/10.3390/nano12040627/s1](https://www.mdpi.com/article/10.3390/nano12040627/s1)]([https://www.mdpi.com/article/10.3390/nano12040627/s1](https://www.mdpi.com/article/10.3390/nano12040627/s1)). Figure S1: **(a)** J-V and **(b)** L-I characteristics of square InGaN-\(\mu\)LEDs with different sizes. Figure S2: The normalized EL spectra of the square \(\mu\)LED with a side length of 80 \(\upmu\)m under different applied voltages. Figure S3: The normalized response of the square \(\mu\)LED with a side length of 80 \(\upmu\)m under a current of 70 mA. The dashed line represents the forward error correction (FEC) threshold.  
Conceptualization, P.T., R.G., L.W. and X.L.; methodology, X.L. and S.M.; formal analysis, X.L., L.T. and S.M.; investigation, X.L., L.T. and D.S.; writing--original draft preparation, X.L. and L.T.; writing--review and editing, X.L., L.T., Z.C., Z.S., P.Y., J.Y., T.Z. and T.T.; supervision, P.T., R.G. and L.W.; project administration, X.L. and P.T.; funding acquisition, X.L., P.T., R.G. and L.W. All authors have read and agreed to the published version of the manuscript.  
Figure 8: **(a)** CIE color coordinates and **(b)** frequency responses of the white light used in the WL-VLC system. The –3 dB modulation bandwidth is marked by a dashed line. Inset: the eye diagram versus the data rate of the system at 90 Mbps.  
**Funding:** This research was funded by the National Key Research and Development Program of China (2021 YFE0105300), Key Technologies R&D Program of Huzhou City Science and Technology Project (2020 GG03), Natural Science Research of Jiangsu Higher Education Institutions of China (20 KJB510014), NJUPTSF (NY220078), the Foundation of Jiangsu Provincial Double-Innovation Doctor Program (JSSCBS20210522), National Natural Science Foundation of China (61974031, 61904087, 61974062), Fudan University-CIOMP Joint Fund (FC2020-001).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Data underlying the results presented in this paper are not publicly available at this time, but may be obtained from the authors upon reasonable request. The data that support the findings of this study are available upon reasonable request from the authors.  
**Conflicts of Interest:** The authors declare no conflict of interest.