Photoconducting and electrical properties of Al/TIPS-pentacene/p-Si/Al hybrid diode for optical sensor applications

Schottky diode based on 6,13 bis (triisopropylsilylethynyle) (TIPS) pentacene was fabricated using spin coating. The junction properties and photoconductivity of the Al/TIPS-pentacene/p-Si/Al diode were studied. The ideality factor and barrier height of the diode were calculated using I–V characteristics and obtained to be 1.97 and 0.65 eV, respectively. The photocurrent of the diode depends on the illumination intensity and increases with increasing photo-illumination intensity. The transient photocurrent results indicate that photocurrent under illumination is higher than the dark current and increases with increase in light intensity. The capacitance of the diode decreases with increasing frequency due to a continuous distribution of the interface states. The linear dependence of the double log plot of photocurrent and light intensity suggests that the Al/TIPS-pentacene/p-Si/Al diode could be used as an optical sensor.