Diffused bulk channels instead of laser drilled via-holes in emitter wrap-through solar cell structure: A simulation study

• Published in: Solar energy Vol. 96; pp. 119 - 127
• Main Authors: Mondal, Som, Thakur, Prasad, Solanki, Chetan Singh
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-10-2013; Elsevier; Pergamon Press Inc
• Subjects: Applied sciences; Carrier separation; Channels; Comparative analysis; Crude oil, natural gas and petroleum products; Diffused channels; Diffusion; Direct energy conversion and energy accumulation; Drilling methods and equipments. Rocks mechanics. Directional and horizontal drilling; Drilling. Casing. Preparing wells for production; Electrical engineering. Electrical power engineering; Electrical power engineering; Emittance; Emitter-wrap-through; Energy; Exact sciences and technology; Fuels; Lifetime; Minority carriers; Natural energy; Performance evaluation; Photoelectric conversion; Photovoltaic cells; Photovoltaic conversion; Prospecting and production of crude oil, natural gas, oil shales and tar sands; Simulation; Simulators; Solar cells; Solar cells. Photoelectrochemical cells; Solar energy; Surface layer; Texture; Emitter-wrap-through; Lifetime; Carrier separation; Diffused channels; Performance evaluation; Drilling; Minority carrier; Conversion rate; Doping; Durability; p n junction; Shadow; Spacing; Solar cell; p type semiconductor; Carrier lifetime; n type semiconductor; System simulation; Surface texture; Simulator; Surface conditions; Comparative study
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2013.07.015

•An emitter wrap-through solar cell structure with diffused channels is proposed.•Simulation studies are done on proposed cell and conventional cell structure.•More than 10% relative gain in efficiency is obtained at several design conditions.•Improvement relies on high carrier collection probability and zero shadow loss.•Proposed solar cell structure is more suitable for low lifetime materials.
An emitter wrap-through solar cell structure with diffused channels instead of drilled via-holes has been proposed in this study. The proposed solar cell, with p–n junctions near the surface and in the bulk, is expected to perform better due to (i) zero shadow loss, (ii) enhanced carrier collection from bulk and (iii) low surface coverage of metal. The device structure is simulated in Synopsys® Sentaurus simulator and is compared to the conventional solar cell structure devoid of surface texture. Variation of solar cell performance due to variations in minority carrier lifetime, channel doping, channel diameter and inter-channel spacing has been studied. It is observed that the bulk minority carrier lifetime and separation between channels affect the performance of the cell more than other parameters. Simulation results show that when electron lifetime in p-type is 10μs and hole lifetime in n-type is 3μs, the proposed solar cell (with small pitch values) gives 17.5% efficiency while conventional solar cell gives 16.1% efficiency. When minority carrier lifetime in p-type is 100μs, the proposed solar cell (with small pitch values) gives 19.2% efficiency.