ELECTRICAL-PROPERTIES OF EPITAXIAL P-N GAP STRUCTURES DEPOSITED ON SI-SUBSTRATES

The electrical properties of p-n-GaP/n-Si structures, grown by the vap or phase epitaxy method in an open Ga(GaP)-PCl3-H-2 system were found to have characteristic features. A considerable reduction in the serie s resistance of the p-n-GaP/n-Si structures, compared with the resista nce of conventional p-n structures made of GaP (on GaP substrates), wa s observed for the first time at liquid-nitrogen temperatures, althoug h at room temperature the resistances of the two types of structure we re nearly the same. A comparatively low series resistance of p-n GaP s tructures on Si substrates made it possible to investigate the mechani sm for the flow of the current at 77 K by direct determination of the current-voltage (1-U(j)) characteristics (U(j) is the voltage across t he space charge layer of the p-n junction). The temperature dependence of the I-U(j) characteristics suggests the presence of a tunnel-exces s mechanism for the flow of the current in the investigated p-n GaP-on -Si structures, which is associated with dislocations. The lower (at 7 7 K) series resistance of p-n-GaP/n-Si structures shifts the lower lim it of the operating temperatures of p-n GaP structures to liquid-nitro gen temperatures, without a change in the upper limit at approximately 400-degrees-C, thus widening the overall operating range.