DEMONSTRATION OF SI HOMOJUNCTION FAR-INFRARED DETECTORS

A 48 mu m cutoff wavelength (lambda(c)) Si far-infrared (FIR) detector is demonstrated. Internal photoemission over a Si interfacial work-fu nction of a homojunction consisting of molecular beam epitaxy grown mu ltilayers (p(+) emitter layers and intrinsic layers) is employed. The detector shows high responsivity over a wide wavelength range with a p eak responsivity of 12.3+/-0.1 A/W at 27.5 mu m and detectivity D of 6.6x10(10) cm root Hz/W. The lambda(c) and bias dependent quantum effi ciency agree well with theory. Based on the experimental results and t he model, Si FIR detectors (40-200 mu m) with high performance and tai lorable lambda(c)s can be realized using higher emitter layer doping c oncentrations. (C) 1998 American Institute of Physics.