This dissertation reports the study of the influence of different deposition techniques on the physical properties of two molecular organic systems: (1) DCM2:Alq3 e (2) [Sm(tta)3(dppmo):Eu(tta)3(dppmo)]. The investigation was carried out by analyzing the optical and electrical characteristics of thin films and organic light-emitting devices (OLEDs) based on the two organic systems. In both systems, one of the compounds was used as the host (Alq3 and Sm-based complex) and the other as the dopant (DCM2 and Eu-based complex). Analysis of the system (1) physical properties, showed that the system response varies as a function of the used deposition technique (in this case, thermal codeposition and spin-coating). For example, the molecular energy-transfer process between the matrix (Alq3) and the dopant (DCM2) varies from one technique to the other, being less efficient in the one where the molecular separation is larger. The study also demonstrated that the energy transfer can be inhibited by means of UV photodegradation process. System (2) was grown by thermal codeposition as well as thermal deposition of molecules mixed in solid phase. In this case, the results indicated that the response of this system is independent of the deposition technique chosen. Besides, doping the Sm(tta)3(dppmo) host with an europium complex allowed to observe not only an intermolecular energytransfer between the two complexes but also an increasing in the emission intensity of some Eu3+ transitions. Both systems can be applied to UV radiation sensors’ fabrication and organic light-emitting devices.