Photovoltaic effect in CuTCNQ organic thin films

An experimental study was carried out of photovoltaic effects occurring in the structure Cu/CuTCNQ/ITO(A1). Prototype devices were fabricated by growing CuTCNQ organic thin films directly on a copper substrate and then laying the semitransparent electrodes (glass/ITO or glass/Al) on the CuTCNQ/Cu. By choosing appropriate conditions for formation of the film in the liquid phase, for example solution temperature, growth time and so on, we obtained an open-circuit voltage Vo~ as high as 2.6 mV, a short-circuit current density J~c of 0.2/aAcm 2 and a fill factor FF of 0.25 for an area of 1.0cm 2 under 0.7W illumination by a laser wavelength 488 nm. The photovoltaic effect increased when the structural resistance was raised by decreasing the contact pressure. There were indications that these effects are mainly due to the characteristics of the CuTCNQ thin films.