Presently, silicon photonics requires photodetectors that are sensitive in a broad infrared range, can operate at room temperature, and are suitable for integration with the existing Si-technology process. Here, we demonstrate strong room-temperature sub-band-gap photoresponse of photodiodes based on Si hyperdoped with tellurium. The epitaxially recrystallized Te-hyperdoped Si layers are developed by ion implantation combined with pulsed-laser melting and incorporate Te-dopant concentrations several orders of magnitude above the solid solubility limit. With increasing Te concentration, the Te-hyperdoped layer changes from insulating to quasi-metallic behavior with a finite conductivity as the temperature tends to zero. The optical absorptance is found to increase monotonically with increasing Te concentration and extends well into the mid-infrared range. Temperature-dependent optoelectronic photoresponse unambiguously demonstrates that the extended infrared photoresponsivity from Te-hyperdoped Si p-n photodiodes is mediated by a Te intermediate band within the upper half of the Si band gap. This work contributes to pave the way toward establishing a Si-based broadband infrared photonic system operating at room temperature.
@article{arxiv.1809.00983,
title = {Extended Infrared Photoresponse in Te-Hyperdoped Si at Room Temperature},
author = {Mao Wang and Y. Berencén and E. García-Hemme and S. Prucnal and R. Hübner and Ye Yuan and Chi Xu and L. Rebohle and R. Böttger and R. Heller and H. Schneider and W. Skorupa and M. Helm and Shengqiang Zhou},
journal= {arXiv preprint arXiv:1809.00983},
year = {2018}
}