Analysing space charge-limited conduction in Au/n-InP Schottky diodes

The theory of space charge limited currents (SCLC) was investigated at the range of 160–300 K temperatures. Current–voltage measurements show that the current flow is space charge limited and influenced by traps. At low voltages, the current density behavior suggests ohmic conductivity, while at higher voltages, a region of space-charge-limited current conduction was observed. Some essential parameters such as trap concentration, characteristic temperature and the trap center density was obtained from the temperature dependent current density in accordance with the theory for the exponential trap distributions. It was concluded that SCLC measurements may also be used to investigate the properties of deep levels in high electron mobility-InP semiconductors with insulators in the presence of interfacial trap states.

Research Highlights► SCLC mechanism is the alternative conduction mechanism for diodes. ► The charge transport depends on the trap density. ► The current transport properties are interpreted via Schottky or the Poole-Frenkel effect. ► Power-law dependence is governed by space charge-limited currents.