The Origin of Localization in Ti-Doped Silicon*

Intermediate band semiconductors hold the promise to significantly improve the efficiency of solar cells, but only if the impurity band is metallic. We apply our recently developed first principles method [1-4] to investigate the nature of localization in Ti-doped Si, a promising candidate for intermediate band solar cells. Our results show that, contrary to common belief, Anderson localization plays a more important role than Mott localization in the metal-insulator transition. Implications for the theory of intermediate band solar cells will be discussed.

[1] T. Berlijn, D. Volja, and W. Ku PRL 106, 077005 (2011)
[2] C. E. Ekuma, H. Terletska, K.-M. Tam, Z.-Y. Meng, J. Moreno, and M. Jarrell, PRB 89, 081107 (2014)
[3] Y. Zhang, H. Terletska, C. Moore, C. Ekuma, K.-M. Tam, T. Berlijn, W. Ku, J. Moreno, and M. Jarrell, PRB 92, 205111 (2015)
[4] Y. Zhang, R. Nelson, E. Siddiqui, K-M Tam, U. Yu, T. Berlijn, W. Ku, NS Vidhyadhiraja, J. Moreno, and M Jarrell, PRB 94, 224208 (2016)