Interdigitated electrode geometry effects on the performance of organic photoconductors for optical sensor applications

This paper studies the electrical characteristics of solution-processed organic photosensors (OPSs) made from organic materials of poly-3-hexylthiophene (P3HT) and [6,6]-phenyl-C61 butyric acid methyl ester (PCBM), with four-type of interdigitated electrodes for achieving high photo-sensing performances. The thin layers of organic material are deposited by spin-coating methods. The current of the OPSs through the semiconductor organic films is measured under light intensities ranging from dark to 300 mW/cm². At 10 V bias and 300 mW/cm² illumination, the currents obtained from pristine P3HT and blended P3HT/PCBM, both spin-coated, are 6.9 × 10^{- 5} mA, and 3.6 × 10^{- 5} mA, respectively. Finally, in order to evaluate the response characteristics under illumination, the current characteristics of the OPS are measured as a function of time and results confirm good reproducibility and fast response times of the OPSs.