Temperature Dependent Dynamics of Charge Carriers in Tellurium-Hyperdoped Silicon

Tellurium-hyperdoped silicon shows significant promise as a candidate as an intermediate band material for highly efficient solar cells and photodetectors. We use Time-Resolved THz Spectroscopy to study excited carrier dynamics of Si hyperdoped with 0.5, 1, and 2 % of Te. Normalized photoconductivity measurements reveal carrier lifetime trend across the sample between 100K and 310K. Consistent with the literature, charge carrier lifetime reduces with increasing dopant concentration. We found that the carrier lifetime becomes less temperature dependent as the dopant concentration increases. The peak photoconductivity changes with temperature which indicates temperature-dependent carrier mobility. In literature, the photodetection range of Te-hyperdoped silicon extends to 5.0 mu m at 20K. Our temperature dependent carrier transport study in hyperdoped silicon reveals charge carrier trapping and carrier mobility at different Te dopant concentrations.