Monolithic photovoltaic PbS-on-Si infrared-sensor array

The growth of epitaxial narrow-gap PbS-on-Si substrates using a stacked CaF/sub 2/-BaF/sub 2/ intermediate buffer layer and the fabrication of linear arrays of photovoltaic infrared (IR) sensors in the PbS layer are discussed. The sensors of the array exhibit resistance-area products at zero bias of 3 Omega -cm/sup 2/ at 200 K (3.4- mu m cutoff wavelength) and 2*10/sup 5/ Omega -cm/sup 2/ at 84 K (4- mu m cutoff), with corresponding detectivities of 2*10/sup 10/ and 1*10/sup 13/ cm- square root Hz/W, respectively.<
>