Humidity influenced capacitance and resistance of an Al/DNA/Al Schottky diode irradiated by alpha particles

Abstract

Deoxyribonucleic acid or DNA based sensors, especially as humidity and alpha particle sensors have become quite popular in recent times due to flexible and highly optimizable nature of this fundamental biomaterial. Application of DNA electronics allow for more sensitive, accurate and effective sensors to be developed and fabricated. In this work, we examined the effect of different humidity conditions on the capacitive and resistive response of Aluminum (Al)/DNA/Al Schottky barrier structure when bombarded by time-dependent dosages of alpha particles. Based on current-voltage profiles, which demonstrated rectifying behaviours, Schottky diode parameters such as ideality factor, barrier height and series resistance was calculated. Results observed generally pointed towards a decrease in the resistance value from the pristine to the radiated structures. It was also demonstrated that under the effect of humidity, the capacitance of the DNA thin film increased from 0.05894 to 92.736 nF, with rising relative humidity level. We also observed the occurrence of the hypersensitivity phenomena after alpha irradiation between 2 to 4 min by observing a drop in the series resistance, crucial in the study of DNA damage and repair mechanisms. These observations may also suggest the exciting possibility of utilizing Al/DNA/Al Schottky diodes as potentially sensitive humidity sensors.

Measuring the Electronic Properties of DNA-Specific Schottky Diodes Towards Detecting and Identifying Basidiomycetes DNA

“…It is a known fact that metal-semiconductive junctions constitute a Schottky junction (Schottky diode), which imparts a rectifying effect on a current-voltage (I-V) profile as observed with a conventional p-n junction 10 . The same was observed with a DNA-metal (semiconductor-metal) junction, which actually constitutes a Schottky diode, and has been published and studied in numerous research papers 11 12 13 14 15 16 . Using conventional analysis technique, various electronic parameters such as ideality factor, barrier height and series resistance can be calculated from the I-V profiles 17 .…”

The synthesis of a Cu0.8Zn0.2Sb2–polyacrylamide nanocomposite by frontal polymerization for moisture and photodetection performance

“…This, in turn, affects the capacitance. 58,59 Among the various test frequencies, 20 Hz exhibits the best linearity for humidity sensing characteristics, so this frequency was selected for determining the other sensing characteristics. The Cu 0.8 Zn 0.2 Sb 2 AAm polymer nanocomposite sensing film showed a linear curve from the 70-95% RH in an increasing mode and 95-75% RH in a decreasing mode at a 20 Hz frequency, which are shown as an inset in Fig.…”

“…The variation of capacitance with operating frequency exhibited an excellent characteristic trend. [58][59][60] It is obvious from the curve that the capacitance (C) changed with increases in frequency. Interestingly, the level of decrease in capacitance value was faster at higher % RH levels compared to lower % RH values.…”

“…In comparison to the conventional polymer-based humidity sensors, the Cu 0.8 Zn 0.2 Sb 2 acrylamide thin-film sensor has proven to be better. [55][56][57][58][59][60][61][62]64 These exceptional characteristics occur because of the repeating units of the monomer CH 2 CH(CONH 2 ). The nitrogen forms hydrogen bonds with water molecules resulting in a strong hydrophilic nature and can form aqueous solutions of a very high concentration.…”

Enhanced moisture sensing properties of a nanostructured ZnO coated capacitive sensor

“…Therefore, it is important to measure precisely the grain moisture levels. The basic principle of a humidity/moisture sensor is based on the change in the refractive index (optical), 2 mass (gravimetric), 3 dielectric constant (capacitive) 4,5 or in the conductivity (resistive) [6][7][8] of the active material with the moisture content. Furthermore, the essential properties of moisture sensors for their extensive use include low cost, high sensitivity, precision and good performance.…”