The effects of illumination on the current conduction mechanisms of the Au/C20H12/n-Si Schottky barrier diode (SBD)

Abstract

Using the I-V characteristics both in the dark and under varied illumination-intensities (50–250 mW.cm−2) by 50 mW.cm−2 steps in the wide range bias-voltage (±5 V), specific fundamental electrical and photo effects parameters of the Au/C20H12/n-Si SBD were examined. Due to the creation of electron–hole pairs and their drift in opposite directions under the influence of an electric field, the value of photocurrent in the reverse bias (Iph) increases when illumination density is increased. The barrier height (ΦB0) tended to decrease due to the increase in photocurrent, while the diode’s ideality factor (n) increased with increasing illumination intensity. Also, the Schottky structure’s open-circuit voltage (Voc), short circuit current (Isc), filling factor (FF), and efficiency (η) were determined to be 0.358 V, 95.5 μA, 33%, and 0.028% under 50 mW.cm−2, respectively. The Rs and Rsh values found using Ohm’s law are a vital function of illumination and voltage which decrease with increasing illumination intensity. Additionally, using the forward bias I-V data and accounting for the bias dependent of the effective barrier height (Φe) and ideality factor n(V) for different illumination intensities, the energy density distribution profile of surface states (Nss) was obtained. According to these results, the organic interlayer consisting of C20H12 is light-sensitive and suitable for optoelectronic devices such as photodetectors and photodiodes.