HgCdTe/Si heterostructures (HSs) were obtained by pulsed laser deposition (PLD) on Si (p- or n-type) flat and patterned (pyramid-like and plate-like) substrate from p- or n-type HgCdTe target. The I-V characteristics of p-n and isotype HSs were investigated by the differential approach. This approach is based on monitoring of differential slope alpha of the I-V characteristics in log-log plot ( alpha = d 1 g I/d 1gV). Influence of the substrate kind (flat, pyramid-like or plate-like), type of conductivity, type of HS (p-n or isotype) and substrate resistivity were studied. In all cases, the main feature of the I-V characteristics behaviour was alpha = 3/2. It means that the bimolecular recombination is the main recombination mechanism in all HSs types.