Electrical analysis of organic interlayer based metal/interlayer/semiconductor diode structures

摘要

In this work, metal/interlayer/semiconductor (MIS) diodes formed by coating of an organic film to p-Si semiconductor substrate were prepared. Metal(Al)/interlayer (phenolsulfonphthalein =PSP)/semiconductor(p-Si) MIS device had a good rectifying behavior. By using the forward bias Ⅰ-Ⅴ characteristics, the values of ideality factor (n) and barrier height (Φ_b) for the Al/PSP/p-Si MIS diode were obtained as 1.45 and 0.81 eV, respectively. It was seen that the Φ_b value of 0.81 eV calculated for the Al/PSP/p-Si MIS diode was significantly larger than value of 0.50 eV of conventional Al/p-Si Schottky diodes. Modification of the interfacial potential barrier of Al/p-Si diode was achieved by using a thin interlayer of the PSP organic material. This has been attributed to the fact that the PSP organic interlayer increases the effective barrier height by influencing the space-charge region of Si. The interface-state density of the MIS diode was determined, and the interface-state density was found to vary from 3.00 ×10~(13) to 2.99 ×10~(12) eV~(-1) cm~(-2).