This study explores the fabrication and performance analysis of ultra-thin III-V solar cells using indium phosphide (InP) epitaxial wafers through two approaches: substrate thinning via lapping and thermocompression bonding. The thinning method reduced the substrate thickness to 160 μm, while the bonding process achieved a final thickness of 0.9 μm. Photoluminescence (PL), internal quantum efficiency (IQE), and external quantum efficiency (EQE) measurements were conducted to evaluate the devices. Results showed that the thinned solar cells exhibited poor photovoltaic characteristics due to suboptimal n-type metal contacts and excessive electron-hole recombination, with no observable light-induced current at zero bias. Backside solar cells fabricated through bonding showed better performance, with improved IQE and EQE due to enhanced light penetration and reduced reflectance from an anti-reflection coating. PL analysis revealed a distinct 1280 nm peak for the backside structure, indicating better light interaction with the active region. Despite these advances, both methods demonstrated low open-circuit current and power efficiency, underscoring the need for further optimization to achieve commercially viable III-V solar cells.

Full-duplex non-orthogonal multiple access wireless networks with energy harvesting have the potential to improve spectral efficiency and save energy. However, wireless signals are susceptible to eavesdropping by other devices within their coverage area. This paper studies the security performance of a full-duplex non-orthogonal multiple access wireless network with energy harvesting (FDNOMAWNwEH) over Nakagami-m fading channels. Results show that the total throughput increases as the power of the primary transmitter increases. Similarly, the total throughput also increases as the expected security level or the energy harvester efficiency increases. In addition, there exists a value of the NOMA power division factor that maximizes the total throughput. Furthermore, the results show that the total throughput decreases as the fading severity parameter increases.

The electricity obtained from the photovoltaic (PV) system highly depends on various factors such as geographical location, solar radiation, weather conditions and orientation of solar panels. The electricity produced by the solar PV system can be assessed by using simulations. This paper presents a technical feasibility assessment of a 10 kWp rooftop solar PV system for a household in Thu Dau Mot City, Vietnam. The study presents the amount of electricity produced, the performance of the PV system and the system potential to reduce CO2 emissions into the environment. The designing and evaluating of the system performance is done by PV*SOL, PVsyst and PVGIS software. The project provides useful information for the pre-feasibility assessment phase of a residential solar PV project in Vietnam.