Recombination behavior and contact resistance of n+ and p+ poly-crystalline Si/mono-crystalline Si junctions

• Published in: Solar energy materials and solar cells Vol. 131; pp. 85 - 91
• Main Authors: Römer, Udo, Peibst, Robby, Ohrdes, Tobias, Lim, Bianca, Krügener, Jan, Bugiel, Eberhard, Wietler, Tobias, Brendel, Rolf
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2014; Elsevier
• Subjects: Applied sciences; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Energy; Exact sciences and technology; Natural energy; Passivated contact; Passivation; Photoelectric conversion; Photovoltaic conversion; Polysilicon; Silicon solar cell; Solar cells. Photoelectrochemical cells; Solar energy; Tunnel oxide; Silicon solar cell; Passivated contact; Polysilicon; Tunnel oxide; Passivation; Silicon solar cells; Oxide layer; Polycrystal; Contact resistance; Open circuit voltage; Solar cell; Crystalline material; Si junctions; Low current; p type semiconductor; n type semiconductor; Series resistance; Current density; Electrical characteristic; Planar technology
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2014.06.003

We present an investigation of the electrical characteristics – recombination and contact resistance – of poly-crystalline (poly) Si/mono-crystalline (c) Si junctions and of the influence of the interfacial oxide between the poly-Si and the c-Si on these characteristics. In particular, we compare thermally grown oxides with different thickness values with wet chemically grown oxides. Both n- and p-type poly-Si emitters are investigated. For one combination (n-type poly-Si, thermal oxide), we compare planar and textured surfaces. For all oxide types investigated, we achieve combinations of low recombination current densities <20fA/cm² and low specific contact resistances <0.1Ωcm². The corresponding implied open-circuit voltages measured on our test structures are 732mV (n-type poly-Si) and 711mV (p-type poly-Si). By applying these poly-Si layers on a solar cell structure, we achieve an open-circuit voltage of 714mV and a series resistance of 0.6Ωcm². •J0 of 5fA/cm² for n-type poly-Si and 10fA/cm² for p-type poly-Si layers achieved.•Contact resistances of poly-Si/c-Si junctions smaller than 0.1Ωcm² achieved.•Voc of 714mV on full poly-Si contacted solar cell device achieved.