Espinet González, Pilar and Romero, R. and Orlando Carrillo, Vincenzo and Gabás, M. and Nuñez Mendoza, Neftali and Vázquez López, Manuel and Palanco, S. and Bijani, S. and Contreras, Y. and Galiana Blanco, Beatriz and Algora del Valle, Carlos and Araki, Kenji
Case study in failure analysis of accelerated life tests (ALT) on III-V commercial triple-junction concentrator solar cells.
In: "39th Photovoltaic Specialists Conference (PVSC)", 16/06/2013 - 21/06/2013, Tampa, Florida. pp. 1666-1671.
In this work the failure analysis carried out in III-V concentrator multijunction solar cells after a temperature accelerated life test is presented. All the failures appeared have been catastrophic since all the solar cells turned into low shunt resistances. A case study in failure analysis based on characterization by optical microscope, SEM, EDX, EQE and XPS is presented in this paper, revealing metal deterioration in the bus bar and fingers as well as cracks in the semiconductor structure beneath or next to the bus bar. In fact, in regions far from the bus bar the semiconductor structure seems not to be damaged. SEM images have dismissed the presence of metal spikes inside the solar cell structure. Therefore, we think that for these particular solar cells, failures appear mainly as a consequence of a deficient electrolytic growth of the front metallization which also results in failures in the semiconductor structure close to the bus bars.