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.
@article{arxiv.1804.06532,
title = {Boron-doping of cubic SiC for intermediate band solar cells: a scanning transmission electron microscopy study},
author = {Patricia Almeida Carvalho and Annett Thørgesen and Quanbao Ma and Daniel Nielsen Wright and Spyros Diplas and Augustinas Galeckas and Alexander Azarov and Valdas Jokubavicius and Jianwu Sun and Mikael Syväjärvi and Bengt Gunnar Svensson and Ole Martin Løvvik},
journal= {arXiv preprint arXiv:1804.06532},
year = {2018}
}