Organic photoconductors photovoltaics

Photocurrent — Contribution to the current in a -+ semiconductor due to photon incidence. For both inorganic and organic photoconductors the light intensity II and the photocurrent Jph are related by Iph = l[y where y is characteristic of the photoconducting system. In photovoltaic devices photocurrent denotes the difference between the -> current generated by the device under illumination and the current with the device in the dark, the dark current. See also photoconductivity. 

Photovoltaic and photoconductive phenomena for various types of CT complexes between saturated polymers and dopant molecules, heterojunctions between polymers and organic and inorganic photoconductors were also investigated in the last few years [86-92]. The quantum efficiency of the energy conversion of 10-3% was obtained for such systems and output power density of 3 x 102 mV cm-2. The mobilities of the heterogeneous polymer systems with despersed inorganic photoconductors reach the value — 10 3-10-4 m2 V 1s 1. 

Whether or not Chi is regarded intrinsically as an organic semiconductor, the solid Chi layer in contact with a metal does display a p-type photovoltaic effect, and its efficiency depends significantly on the morphology of the Chi layer as well as the nature of the metal. The effect corresponding to a p-type photoconductor can also be expected at the junction of a metal / Chi / liquid in a photoelectrochemical system. Such a presumption is in fact compatible with the photoelectrochemical behavior observed for most of Chl-coated metal electrodes, as will be shown later. 

Present interest in disc-like aromatic molecules results mainly from their application as ID charge carrier materials for use in photoconductors, light emitting devices, organic transistors, and photovoltaic applications [265]. 

OPVs are suitable for various applications in materials science Organic light emitting diodes (OLED), field-effect transistors (FET), semiconductors (doped), photoconductors, solar cells, photovoltaic devices, optical brighteners, laser dyes, nonlinear optics (NLO), optical switching, imaging techniques, photoresists and liquid crystals [la-e, Ij-o, Ir, Iv, 27, 120]. Among these applications, two fields will be selected here, namely NLO and electroluminescence studies. 

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