## 1 Introduction
Li-Fi is a modern technology that uses the principle of illumination as a way of data transmission using visible light and is analogous to Wi-Fi, which uses radio frequency for communication. Li-Fi is capable of achieving a speed of up to10 Gbps, which is 250 times faster than the speed of super-fast broadband, and Li-Fi can also be a workaround if there is concern about electromagnetic interference in aircraft, hospitals, etc. where RF communication is forbidden [6; 10]. Nonetheless, one cannot simply use a light bulb to relay data to fast-moving objects or objects behind walls, because Li-Fi is a complementary technology that helps to address the problems faced by the current technology. VLC can also be used as a suitable replacement for RF waves in underwater communication, because RF signals cannot propagate well in seawater due to the salty, high conductivity and high attenuation of seawater environments [15; 16]. Yet, sound waves have a low propagation rate, limited bandwidth, and high power requirement when traveling deep into the ocean, as well as being likely to interfere with marine animals, such as dolphins. In making use of visible light for data communication, VLC can efficiently solve these limitations of radio wave and sound waves in underwater communication. Nevertheless, the use of VLC for underwater communication raises some concerns as the rate of data transmission and the distance may be severely affected when the water loses its clarity due to the existence of suspended particulates, i.e., turbidity [17]. VLC may be used to avoid accidents by communicating between vehicles with regard to pre-crash sensing, warning of collision, warning of lane change, warning of traffic signal violation, etc., as accident risks are rising in developing countries [18]. Since these kinds of applications require reliable reachability and low latency, a high-speed visible light communication system like Li-Fi is needed. However, VLC implementation will face some challenges, including interference with the ambient light sources, interference with other VLC devices, and VLC integration with existing technologies such as Wi-Fi [6]. LEDs have gained significant interest for high-speed VLC applications due to their outstanding features, such as low cost, low-power consumption, offering multiplexing options for wavelengths, and compatibility with existing solid-state lighting systems [1]. However, conventional polar LEDs grown on the c-plane have limited bandwidth, especially in the green spectral region due to their inbuilt piezoelectric polarization [19]. This polarization in c-plane-oriented InGaN quantum wells separates electrons and holes, thus increasing the time of radiative recombination resulting in a strong Quantum Confined Stark Effect (QCSE) [20; 21]. The QCSE may not only cause a substantial peak change, but also a major drop in luminous efficiency under high injection current, resulting in considerable device performance degradation along with Auger effects [20; 22]. By growing the quantum wells in semipolar or nonpolar orientations, this polarization field can be reduced or eliminated. This allows for better overlapping of the electron and hole and faster radiative recombination, especially in thicker quantum wells [23; 24; 25; 26]. For such crystal orientations, higher electro-optic bandwidths can thus be expected along with potentially reduced Auger effects. Due to the advantages provided by semipolar LEDs in luminous efficiency and stable wavelengths of light, its functionality has been expanded in applications such as high-resolution display, high-speed visible light communication, and, thus, researchers have begun to commit their efforts to the development of semipolar GaN-based LEDs. Nonetheless, a better VLC implementation includes improving the modulation characteristics of the LED light source and the emission efficiency under high-speed modulation.