Hole transport parameters in a PTOPT based organic solar cell

The photovoltaic and charge transport properties of solar cells whose active layer is made from poly[3-(4-octylpheny1)-2. 2'-bithiophene](PTOPT) was studied. Devices are prepared in a sandwich-type structure of the form AI/PTOPT/PEDOT:PSS/ITO. The diodes showed good rectification needed for the PV cell. The symmetric nature of the semilogarithmic J-V plot under dark and low temperature reveals that there is a unipolar charge injection in both sides of the electrodes. Based on the space charge limited region J-V data, it was possible to study the electric field dependence of the hole transport, which enable us to derive important parameters such as the zero field mobility (mu(0)) and the field activation factor (gamma).