InGaN photovoltaic converters: Processing approaches for high-power optical transmission

This work explores the processing of InGaN semiconductors as high-power optical transmission (HPOT) photovoltaic converters (OPCs). Current HPOT systems present limitations in efficiency and power density, primarily due to materials with low band gaps, such as GaAs, with significant losses at high irradiances due to series resistance issues. InGaN offers a promising alternative for overcoming these limitations. However, there is a lack of studies and experimental results about this material for HPOT. This work reviews the state-of-the-art in OPCs, highlighting the potential of InGaN to outperform conventional technologies. Growth techniques, doping strategies and fabrication methods of InGaN-based OPCs are investigated. The work examines Molecular Beam Epitaxy (MBE) and Metalorganic Vapor Phase Epitaxy (MOVPE) as growth techniques, emphasizing the advantages of MBE, particularly when combined with metal modulated epitaxy (MME), for producing high-quality InGaN films. The challenges associated with p-type doping in InGaN and the methods to address them are discussed. Furthermore, the study analyses crucial steps including wafer and substrate preparation, metallic contact formation, anti-reflective coating deposition and cutting. Novel advancements that improve control and precision and enhance device performance are presented. Additionally, a flowchart for InGaN-based OPCs fabrication is proposed, prioritizing high efficiency and power density conversion. This guides the process from substrate preparation to the final device, incorporating techniques like MME growth, GaN substrates with buffer layers and stealth dicing. This research aims to advance understanding and development of InGaN semiconductors for HPOT, addressing limitations and exploring the technology's potential to revolutionize power transmission in the 21st century. • Current HPOT systems are limited in efficiency and power density conversion. • InGaN offers a promising alternative for overcoming these limitations. • Fabrication and processing of InGaN-based OPCs is investigated. • Growth, doping, substrates, light trapping and metallic contacts are addressed. • A flowchart for InGaN-based HPOT OPCs manufacturing is proposed.