Prospects for Infrared Electroluminescence From Porous Silicon

Efficient visible luminescence from porous Si requires the 3-dimensional confinement of charges in structures with typical ∼3nm size. Such microporously etched Si acts as an intrinsic wide-gap material and is highly resistive. The material does not have the good transport properties consistent with an efficient electrical excitation. We instead suggest to employ mesoporously etched, p + -type Si with its better conductivity in electroluminescence application. The material luminesces in two spectral bands centered about 0.8eV and 1.0eV in the infrared. Both emissions originate from surface-bound states. We report on the temperature dependence of luminescence, on transport and first attempts to generate infrared light by the injection of electrical current.