Conducting polymer based heterojunctions have been intensively studied because of prominent application in photovoltaic solar cells. It is reported in this work the formation, environmental conditions, of hybrid heterojunctions of cadmium selenide (CdSe) poly 30 ctylthiophene (P3OT) by casting a chemically synthesized P3OT solution onto chemical bath deposited (CBD) or screen-printed (SP) CdSe coatings. By using ITO as contact and gold (Au), silver (Ag) or copper (Cu) as metal contact, the electrical properties CdSe–P3OT heterojunctions were studied at room temperature under environmental conditions. In the case of Au contact, the curves of current density (J) vs. applied potential (V) of both (SP) and CdSe (CBD) coatings indicate that the contacts are quasi ohmic. However, with same metal contact the electrical behavior of CdSe (SP)-doped P3OT heterojunction rectifying and the rectification ratio increases as the weight percentage of P3OT increases in heterojunction structure. Furthermore, a small photovoltage (39 mV) was observed in the hybrid structure for Cu contact. On the other hand, for a CdSe (CBD)-pristine heterojunction Au contact gives an ohmic behavior, but rectifying J-V curves are found with contact.