The interface between CdTe epilayers grown by metal organic chemical vapor deposition (MOCVD) and CdTe substrates is studied. Three limiting cases typically encountered in practice during growth runs are presented: (i) a fixed or negligible interface charge; (ii) a variable interface charge that depends on band bending; (iii) a modified non uniform doping profile of the substrate near the interface. Capacitance-voltage (C-V) characteristics of Schottky contacts formed on epilayers and substrates are analyzed for the three limiting cases. Experimental results and the technology designed to improve the interface and CdTe epilayers grown by MOCVD are reported and illustrate the interface analysis.