Vertical-Tunnel-Junction (VTJ) Solar Cell for Ultra-High Light Concentrations (>2000 Suns)

A novel architecture of cell structure tailored to ultra-high (>2000 suns) concentration ratios is proposed. The basic solar cell consists of two p-n junctions connected in series by a highly doped tunnel diode with the metallic contacts located laterally. The tunneling connection allows using direct band-gap semiconductor compounds aiming to optimize the absorption of the spectrum. The performance of the novel architecture is investigated up to ultra-high concentration using TCAD software. Simulations show its viability for developing a new generation of solar cells to increase the potential in terms of efficiency and cost reduction of ultra-high concentrator systems. The solar cell does not show any degradation with concentration and efficiency as high as 28.4% at 15000 suns has been obtained for a preliminary designThe work of E. F. Fernández and F. Almonacid was supported by the Spanish Economy Ministry and FEDER funds under Project ENE2016-78251-R. The work of N. Seoane and A. J. García-Loureiro was supported in part by the Spanish Ministry of Economy and Competitiveness and FEDER funds under Grants TEC2014-59402-JIN and TIN2016-76373-P and in part by the Xunta de Galicia and FEDER funds under Grant GRC 2014/008S