Record-Breaking-High-Responsivity Silicon Photodetector at Infrared 1.31 and 1.55 μm by Argon Doping Technique

The introduction of intermediate band (IB) into the bandgap of silicon (Si) is an efficient way to enhance light absorption of Si in the short-wave infrared region. In this article, we report inert element argon (Ar)-hyperdoped Si ( $\sim$ 10 $^{\text{21}}$ cm $^{-\text{3}}\text{)}$ materials and photodetectors by double-doping technique of ion-implantation followed by pulsed laser doping. The pulsed laser irradiation after ion-implantation process can not only serve as postannealing to improve the crystalline quality of ion-implanted layer, but also be used for re-hyperdoping of Ar atoms to enhance the infrared absorptance ( $\sim$ 20% at 1.31 $\mu$ m) of Ar-hyperdoped Si. The n $^{+}$ -n-junction based on the build-in carrier concentration difference between Ar-hyperdoped layer and Si substrate shows perfect rectification characteristics. The Ar-hyperdoped Si double-contacts photodiodes show the responsivity of 0.975 A/W for 1.31 $\mu$ m and 1.28 A/W for 1.55 $\mu$ m at 12-V reverse bias, respectively. To the best of our knowledge, they are the record-breaking performances for bulk Si photodetector at these subbandgap wavelengths working at a mild voltage. This work demonstrates the potential application of inert element-hyperdoped Si in the field of infrared photodetection.