The influence of environmental conditions “film thickness and measurements in both under vacuum and in air” on dark electrical resistivity of (E) [α(2,5Dimethyl furyl) Ethylidene] (Dicyclopropyl Methylene) 2,5 furadione thin films were investigated. It was found that electrical resistivity decreases exponentially with increasing film thickness and it is higher in those films measured under vacuum than those measured in air. The parameters and mechanisms of conduction in P-DCPF/n-Si heterojunction diode has been evaluated. For temperatures that is less than 351 K, the conduction mechanism is Schottky emission with thermal activation energy of 0.32 eV. In the temperature range “352−400 K”, the predominant conduction mechanism is space charge limited current with thermal activation energy of 0.95 ± 0.02 eV. The conduction mechanism in reverse bias direction is generation-recombination with activation energy of 0.57 ± 0.02 eV. The photovoltaic properties of P-DCPF/n-Si heterojunction diode were evaluated. The obtained experimental efficiency of constructed solar cell is 1.27%.