Electronic properties of Al/DNA/p-Si MIS diode: Application as temperature sensor

The current-voltage (I-V) measurements were performed in the temperature range (200-300 K) on Al/DNA/p-Si Schottky barrier type diodes. The Schottky diode shows non-ideal I-V behaviour with ideality factors n equal to 1.34 ± 0.02 and 1.70 ± 0.02 at 300 K and 200 K, respectively, and is thought to have a metal-interface layer-semiconductor (MIS) configuration. The zero-bias barrier height Φ_b determined from the I-V measurements was 0.75 ± 0.01 eV at 300 K and decreases to 0.61 ± 0.01 eV at 200 K. The forward voltage-temperature (V_F-T) characteristics were obtained from the I-V measurements in the temperature range 200-300 K at different activation currents (I_F) in the range 20 nA-6 μA. The V_F-T characteristics were linear for three activation currents in the diode. From the V_F-T characteristics at 20 nA, 100 nA and 6 μA, the values of the temperature coefficients of the forward bias voltage (dV_F/dT) for the diode were determined as −2.30 mV K⁻¹, −2.60 mV K⁻¹ and −3.26 mV K⁻¹ with a standard error of 0.05 mV K⁻¹, respectively.     

Current–voltage and capacitance–voltage characteristics of a Sn/Methylene Blue/p-Si Schottky diode

Electrical and interfacial properties of Sn/Methylene Blue (MB)/p-Si Schottky diode have been determined by using current–voltage (I–V) and capacitance–voltage (C–V) measurements of the device at room temperature. Cheung functions and modified Norde functions have been used to obtain the electrical characteristics such as barrier height and series resistance of the diode. It has been seen that the MB layer modifies the effective barrier height of the structure because the layer creates the physical barrier between the metal and the semiconductor. Electrical properties of the device obtained from C–V characteristics have been compared with the ones obtained from its I–V characteristics. It has been seen that at sufficiently high frequencies, the charge at the interface cannot follow an ac signal. The interface state density of the diode has been also calculated.