Characterization of epitaxial n-GaP/p-PSi heterojunctions

The liquid phase epitaxy technique was used to fabricate heterojunction devices of n-GaP thin films grown on porous p-Si substrates. XRD and SEM techniques were used to investigate the structure of the GaP grown. Measurements of the current–voltage (I–V) and the capacitance–voltage (C–V) characteristics were evaluated to identify the mechanisms of barrier formation and consequently current flow. The results showed that forward current involves tunneling. It was explained in light of a multi-step tunneling recombination model due to a high density of interface defects. On the other hand, the reverse current seems to be limited by the generation mechanism. The C–V characteristics indicated an abrupt heterojunction model. In addition, various junction parameters were determined from the I–Vand C–V characteristics.