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 Φb 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 (VF–T) characteristics were obtained from the I–V measurements in the temperature range 200–300 K at different activation currents (IF) in the range 20 nA–6 μA. The VF–T characteristics were linear for three activation currents in the diode. From the VF–T characteristics at 20 nA, 100 nA and 6 μA, the values of the temperature coefficients of the forward bias voltage (dVF/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.

Research highlights▶ This work proposes that DNA molecules should be considered, among other candidates, as a potential organic thin film for metal-interface layer-semiconductor devices. ▶ We successfully fabricated Al/DNA/p-Si device with interlayer by a simple cast method. ▶ The temperature is found to significantly effect the electrical properties of the Al/DNA/p-Si device. ▶ The facts: (i) that the technology of the fabrication of a Al/DNA/p-Si Schottky diode much simpler and economical than that for the Si p–n junction and (ii) the sensibility of the Al/DNA/p-Si Schottky diode as temperature sensor is 42% higher than that of a Si p–n junction, indicate that the Al/DNA/p-Si Schottky diode is a good alternative as temperature sensor.