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arXiv · 1804.06532

Boron-doping of cubic SiC for intermediate band solar cells: a scanning transmission electron microscopy study

Patricia Almeida Carvalho·Annett Thørgesen·Quanbao Ma·Daniel Nielsen Wright·Spyros Diplas·Augustinas Galeckas·Alexander Azarov·Valdas Jokubavicius·Jianwu Sun·Mikael Syväjärvi·Bengt Gunnar Svensson·Ole Martin Løvvik
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Abstract

Boron (B) has the potential for generating an intermediate band in cubic silicon carbide (3C-SiC), turning this material into a highly efficient absorber for single-junction solar cells. The formation of a delocalized band demands high concentration of the foreign element, but the precipitation behavior of B in the 3C polymorph of SiC is not well known. Here, probe-corrected scanning transmission electron microscopy and secondary-ion mass spectrometry are used to investigate precipitation mechanisms in B-implanted 3C-SiC as a function of temperature. Point-defect clustering was detected after annealing at 1273 K, while stacking faults, B-rich precipitates and dislocation networks developed in the 1573 - 1773 K range. The precipitates adopted the rhombohedral B13C2 structure and trapped B up to 1773 K. Above this temperature, higher solubility reduced precipitation and free B diffused out of the implantation layer. Dopant concentrations E19 at.cm-3 were achieved at 1873 K.

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Patricia Almeida Carvalho, Annett Thørgesen, Quanbao Ma, Daniel Nielsen Wright, Spyros Diplas, Augustinas Galeckas, Alexander Azarov, Valdas Jokubavicius, Jianwu Sun, Mikael Syväjärvi, Bengt Gunnar Svensson, Ole Martin Løvvik. 2018-04-18. Boron-doping of cubic SiC for intermediate band solar cells: a scanning transmission electron microscopy study. https://doi.org/10.21468/scipostphys.5.3.021

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