This study presents a systematic investigation of the influence of gold nanoparticles on the performance of a metal-semiconductor-metal self-powered 4H-Silicon carbide ultraviolet photodetector (SiC-UVPD) through nonsymmetric contact phenomenon under 254 nm UV-light exposure. Ultraviolet photodetectors attract great interest due to their broad range of applications such as optical communications, pharmaceutical, and chemical analysis, environmental sensing, flame detection, biomedical electronics, missile detection, and space communications. Self-powered photodetectors are desirable devices for green energy applications due to their unique advantages such as smaller footprints and wireless operation. Thus, improving the performance of these devices has become very crucial for the fabrication of efficient, sustainable, energy and environment friendly devices. Metal nanoparticles on a semiconductor surface can enhance the scattering of the incident photons and increase the optical absorption around each particle on the active region of the semiconductor leading to a performance enhancement for the photodetector. Considering this, the SiC-UVPD was fabricated via a highly practical and cost-effective fabrication scheme. A physical mask and a sputter coater system were used to deposit asymmetrical electrodes with a 50 µm spacing. To investigate the influence of gold nanoparticles on the performance of the photodetector, the surface of the fabricated SiC-UVPD was coated with gold for 5 s, 10 s, 15 s, and 20 s deposition times. Following each deposition step, the SiC-UVPD was heated at 150°C for five minutes to transform the deposited gold film into nanoparticles. Fig. 1 shows a scanning electron microscopy image of the Au nanoparticles on the SiC-UVPD surface and a schematic diagram of the measurement setup of the self-powered SiC-UVPD. The size of the Au nanoparticles ranges from 30 nm to 40 nm for 15 s and 20 s deposition times, respectively. To evaluate performance characteristics of the SiC-UVPD, current-time (I-t) measurements were performed through 20-s multiple cycles under two UV light at 0 V through a sourcemeter (Keithley 2634B), which is attached to a probe station and controlled with a Labview program. Fig. 2 displays the I-t plots of the SiC-UVPD following the applications of Au nanoparticles with different surface densities (from 5-s to 20-s Au deposition) at 0 V, revealing strong enhancements in photocurrent. In fact, the ION/IOFF ratio gradually increases with the increase of Au deposition time reaching to a maximum on/off current ratio of 934 with 15-s Au deposition under 254 nm of UV light. However, a slight decrease on the ION/IOFF ratio (870) is observed with 20-s Au deposition under 254 nm UV light. The fabricated SiC-UVPD exhibited a very good sensitivity of 9.34 x 104, great responsivity of 0.30 A/W, and excellent detectivity of 7.0 x 1011 cm. Hz1/2.W-1 under 254 nm UV light without any external power. In fact, the specific detectivity of the self-powered SiC-UVPD improved by 70 % following the application of Au nanoparticles. Combined with the practical and cost-effective fabrication, the self-powered SiC-UVPD can lead the path towards novel, high performance, emerging sustainable energy, and eco-friendly optoelectronic devices particularly for harsh environments.