Pentacene thin-films were obtained by thermal evaporation in high vacuum of a pure (98%) commercially available source. All the samples were grown at room temperature (25 degreesC) and high deposition rates (>20 Angstrom/s) on Corning glass substrates. The microstructure of the pentacene thin-films evidences the coexistence of thin-film and bulk triclinic crystalline phases. The optical absorption edge close to 1.7 eV, together with the high optical absorption in the visible range, make pentacene a promising candidate for low cost solar cells. Doping series of samples were obtained by dipping pieces cut from the same pentacene sample into a solution of iodine in acetonitrile for different times (< 1 h). Thereby, room temperature dark conductivity changes from 3 X 10(-7) to 4x10(-5) Omega(-1) cm(-1). Finally, glass/SnO/pentacene/Al and glass/ZnO:Al/pentacene/Au structures were fabricated showing rectifying characteristics with on/off ratios of approximately 3 orders of magnitude.