Properties of interfaces in amorphous/crystalline silicon heterojunctions

• Published in: Physica status solidi. A, Applications and materials science Applications and materials science, 2010-03, Vol.207 (3), p.651-656
• Main Authors: Olibet, Sara, Vallat-Sauvain, Evelyne, Fesquet, Luc, Monachon, Christian, Hessler-Wyser, Aïcha, Damon-Lacoste, Jérôme, De Wolf, Stefaan, Ballif, Christophe
• Format: Article
• Language: English
• Subjects: 68.35.Ct; 68.37.Lp; 72.20.Jv; 73.20.At; 73.40.Lq; 73.61.Jc; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron states and collective excitations in thin films, multilayers, quantum wells, mesoscopic and nanoscale systems; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Physics; Thin films and multilayers
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.200982845

To study recombination at the amorphous/crystalline Si (a‐Si:H/c‐Si) heterointerface, the amphoteric nature of silicon (Si) dangling bonds is taken into account. Modeling interface recombination measured on various test structures provides insight into the microscopic passivation mechanisms, yielding an excellent interface defect density reduction by intrinsic a‐Si:H and tunable field‐effect passivation by doped layers. The potential of this model's applicability to recombination at other Si heterointerfaces is demonstrated. Solar cell properties of a‐Si:H/c‐Si heterojunctions are in good accordance with the microscopic interface properties revealed by modeling, that are, e.g., slight asymmetries in the neutral capture cross‐sections and band offsets. The importance of atomically abrupt interfaces and the difficulties to obtain them on pyramidally textured c‐Si is studied in combination with transmission electron microscopy.