Extraction of J-V, G/ω-V-f and C-V-f Characteristics for p-Type Silicon/Intrinsic Ultrananocrystalline Diamond/n-Type Nanocrystalline Iron Disilicide Heterojunction Photodiodes.

The production of p-type silicon/intrinsic ultrananocrystalline diamond/n-type nanocrystalline iron disilicide heterojunction devices was conducted via coaxial arc plasma deposition and pulsed laser deposition. The results of current density-voltage (J-V) curves justified a large leakage current along with minimal response under illumination. A recombination process controls the mechanism for carrier portage in the zone of V ≤ 0.16 V, while a space-charge-limited current process governs the carrier portage mechanism in the circumstance of V value beyond 0.16 V. Frequency (f) dependent conductance (G/ω)-V and capacitance (C)-V curves were measured to extract the series resistance (Rs) and density of the interface state (nss). On the basis of extraction in the manner of Nicollian-Brews, the value of Rs rose with f abatement. With zero bias voltage applied, the value of Rs was 189.84 Ω at 2 MHz and rose to 715.10 Ω at 20 kHz. The acquired Rs may be attributable to the occurrence of Rs in the neutral zones as well as Ohmic contact. The values for nss, which were extracted in the manner of Hill-Coleman, were 1.23×1011 eV-1 cm-2 at 2 MHz and 6.51×1012 eV-1 cm-2 at 20 kHz. This result was an indicator of the occurrence of interface states at the zone of the junction interface performing as a source of leakage current and a trap center for the carriers originated by light.