Low temperature intermediate band metallic behavior in Ti implanted Si

Si samples implanted with very high Ti doses and subjected to Pulsed-Laser Melting (PLM) have been electrically analyzed in the scope of a two-layer model previously reported based on the Intermediate Band (IB) theory. Conductivity and Hall effect measurements using the van der Pauw technique suggest that the insulator–metal transition takes place for implantation doses in the 1014–1016 cm− 2 range. Results of the sample implanted with the 1016 cm− 2 dose show a metallic behavior at low temperature that is explained by the formation of a p-type IB out of the Ti deep levels. This suggests that the IB would be semi-filled, which is essential for IB photovoltaic devices.

► We fabricated high dose Ti implanted Si samples for intermediate band research. ► We measured the electronic transport properties in the 7–300 K range. ► We show an insulator to metallic transition when the intermediate band is formed. ► The intermediate band is semi-filled and populated by holes. ► We satisfactorily explain the electrical behavior by an intermediate band model.