A 48 μm cutoff wavelength (λc) Si far-infrared (FIR) detector is demonstrated. Internal photoemission over a Si interfacial work-function of a homojunction consisting of molecular beam epitaxy grown multilayers (p+ emitter layers and intrinsic layers) is employed. The detector shows high responsivity over a wide wavelength range with a peak responsivity of 12.3±0.1 A/W at 27.5 μm and detectivity D* of 6.6×1010 cm Hz /W. The λc and bias dependent quantum efficiency agree well with theory. Based on the experimental results and the model, Si FIR detectors (40-200 μm) with high performance and tailorable λcs can be realized using higher emitter layer doping concentrations.
All Science Journal Classification (ASJC) codes