The compact and oriented TiO2 films are prepared by a solvothermal method, and used as electron transporting layers in perovskite CH3NH3PbI3-xClx based solar cells incorporating poly(3-hexylthiophene-2,5-diyl) (P3HT) as the hole transporting material layer. The devices with P3HT exhibit a substantial increase in power conversion efficiency, open circuit voltage, and fill factor, compared with the reference device without P3HT. Impedance spectroscopy measurements demonstrate that the present P3HT layer decreases the internal resistance in solar cells and allows the interface between oriented TiO2 and CH3NH3PbI3-xClx to form more perfect in electronics. It is also found that the electron lifetime in the devices with P3HT is much longer than that of the device without P3HT. Thus, the charge collection efficiency of the device with P3HT is markedly enhanced, compared with the devices without P3HT. Analysis of the energy levels of the involved materials indicates that the P3HT film between the CH(3)NH(3)Pbl(3-x)Cl(x) layer and the Au electrode provides a better energy level matching for efficient transporting holes to the anode. Meanwhile, the stability of such P3HT solar cells is enhanced because of the compact and oriented TiO2 film preventing the possible interaction between TiO2 and perovskite as time went on. (C) 2014 Elsevier B.V. All rights reserved.