Analysis of microstructure, chemical state and electrical features of Ti/WO₃/p-InP heterojunction with a tungsten oxide insulating layer

This paper examined the fabrication, structural, chemical and electrical features of Ti/WO₃/p-InP heterojunction (HJ). AFM, FESEM and XPS analyses were accomplished to investigate the structural and chemical possessions of the tungsten oxide. The electrical and current transport properties of Ti/p-InP Schottky diode (SD) and HJ were investigated by using the current–voltage (I–V) technique. The HJ exhibits lesser reverse leakage current and enhanced barrier height than the SD. The barrier height (Φ _b) and ideality factor (n) values of SD and HJ are found to be 0.73 eV, 2.27 and 0.83 eV, 1.72, respectively. The inclusion of the WO₃ layer between Ti and p-InP considerably improved the Φ _b of SD. The Φ _b and n were determined using multiple methods including I–V, Cheung’s function and Ψs-V plot, the extracted Φ _b and n values were found to be consistent with one another, indicating the stability and validity of the results. Results revealed that the HJ shows improved Φ _b and n values compared to the SD. The density of states (N _SS) of the HJ was found to be lower than the SD, specifying the effectiveness of the WO₃ insulating layer in reducing N _SS. Both SD and HJ exhibited Poole–Frenkel emission as the prevailing mechanism in the reverse current. These findings suggest that the WO₃ insulating materials have the potential to develop HJ devices.