Facile fabrication and electrical investigations of nanostructured p-Si/n-TiO₂ hetero-junction diode

In this work, we have fabricated the nanostructured p-Si/n-TiO₂ hetero-junction diode by using a facile spin-coating method. The XRD analysis suggests the presence of well crystalline anatase TiO₂ film on Si with small grain size (∼16 nm). We have drawn the band alignment using Anderson model to understand the electrical transport across the junction. The current-voltage (J-V) characteristics analysis reveals the good rectification ratio (10³ at ± 3 V) and slightly higher ideality factor (4.7) of our device. The interface states are responsible for the large ideality factor as Si/TiO₂ form a dissimilar interface and possess a large number of dangling bonds. The study reveals the promises to be used Si/TiO₂ diode as an alternative to the traditional p-n homo-junction diode, which typically require high budget.