Characteristics of a Si dual-band detector responding in both near- and very-long-wavelength-infrared regions

A p-type Si homojunction detector responding in both near- and very-long-wavelength-infrared (NIR and VLWIR) ranges is demonstrated. The detector consists of a p(++)-Si top contact layer, a p(+)-Si emitter, an undoped Si barrier, and a p(++)-Si bottom contact layer grown on a Si substrate. Interband and intraband transitions lead to NIR and VLWIR responses, respectively. The responsivity, quantum efficiency, and detectivity at -1 V bias and 4.6 K are similar to 0.024 A/W, 3.7%, and similar to 1.7x10(9) cm Hz(1/2)/W at 0.8 mu m, while they are 1.8 A/W, 8.8%, and similar to 1.2x10(11) cm Hz(1/2)/W at 25 mu m, respectively. The background limited infrared performance temperature at +/- 0.9 V bias is 25 K. (c) 2006 American Institute of Physics.