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Electronic Properties of DNA-Based Schottky Barrier Diodes in Response to Alpha Particles.

Al-Ta'ii HM, Periasamy V, Amin YM - Sensors (Basel) (2015)

Bottom Line: Various diode parameters such as ideality factor, barrier height, series resistance, Richardson constant and saturation current were then determined using conventional, Cheung and Cheung's and Norde methods.Generally, ideality factor or n values were observed to be greater than unity, which indicates the influence of some other current transport mechanism besides thermionic processes.These responses demonstrate that changes in the electrical characteristics of the metal-semiconductor-metal diode could be further utilized as sensing elements to detect alpha particles.

View Article: PubMed Central - PubMed

Affiliation: Low Dimensional Materials Research Centre (LDMRC), Department of Physics, University of Malaya, 50603 Kuala Lumpur, Malaysia. hassankirkukly@gmail.com.

ABSTRACT
Detection of nuclear radiation such as alpha particles has become an important field of research in recent history due to nuclear threats and accidents. In this context; deoxyribonucleic acid (DNA) acting as an organic semiconducting material could be utilized in a metal/semiconductor Schottky junction for detecting alpha particles. In this work we demonstrate for the first time the effect of alpha irradiation on an Al/DNA/p-Si/Al Schottky diode by investigating its current-voltage characteristics. The diodes were exposed for different periods (0-20 min) of irradiation. Various diode parameters such as ideality factor, barrier height, series resistance, Richardson constant and saturation current were then determined using conventional, Cheung and Cheung's and Norde methods. Generally, ideality factor or n values were observed to be greater than unity, which indicates the influence of some other current transport mechanism besides thermionic processes. Results indicated ideality factor variation between 9.97 and 9.57 for irradiation times between the ranges 0 to 20 min. Increase in the series resistance with increase in irradiation time was also observed when calculated using conventional and Cheung and Cheung's methods. These responses demonstrate that changes in the electrical characteristics of the metal-semiconductor-metal diode could be further utilized as sensing elements to detect alpha particles.

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The relation between the series resistance and voltage generated using conventional method (a) before and (b) after 24 h.
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sensors-15-11836-f004: The relation between the series resistance and voltage generated using conventional method (a) before and (b) after 24 h.

Mentions: The values of series resistances were calculated from the junction resistance (RS = ) obtained from the I-V properties of the diode. Resistance, RSvs. voltage on the surface-type (Al/DNA/Si/Al) Schottky diode is shown in Figure 4. From the figure, it can be concluded that at low voltages (≤1.5 V), RS values were the lowest except for the non-radiated samples, radiated for 10 and 20 min and for the Al/Si/Al junction. For irradiation periods beyond 24 h, the lowest values occur before radiation and at 2 and 8 min. However, above 2.0 V, the RS value becomes insignificant for the latter sample. The highest RS values occur in the sample radiated for 20 min followed by samples irradiated for 10 and 6 min. In the cases for after 24 h, the same trend was observed for samples radiated for 20, 6 and 4 min. This may refer to the phenomenon of DNA protecting itself by increasing its’ series resistance [23,24].


Electronic Properties of DNA-Based Schottky Barrier Diodes in Response to Alpha Particles.

Al-Ta'ii HM, Periasamy V, Amin YM - Sensors (Basel) (2015)

The relation between the series resistance and voltage generated using conventional method (a) before and (b) after 24 h.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4481900&req=5

sensors-15-11836-f004: The relation between the series resistance and voltage generated using conventional method (a) before and (b) after 24 h.
Mentions: The values of series resistances were calculated from the junction resistance (RS = ) obtained from the I-V properties of the diode. Resistance, RSvs. voltage on the surface-type (Al/DNA/Si/Al) Schottky diode is shown in Figure 4. From the figure, it can be concluded that at low voltages (≤1.5 V), RS values were the lowest except for the non-radiated samples, radiated for 10 and 20 min and for the Al/Si/Al junction. For irradiation periods beyond 24 h, the lowest values occur before radiation and at 2 and 8 min. However, above 2.0 V, the RS value becomes insignificant for the latter sample. The highest RS values occur in the sample radiated for 20 min followed by samples irradiated for 10 and 6 min. In the cases for after 24 h, the same trend was observed for samples radiated for 20, 6 and 4 min. This may refer to the phenomenon of DNA protecting itself by increasing its’ series resistance [23,24].

Bottom Line: Various diode parameters such as ideality factor, barrier height, series resistance, Richardson constant and saturation current were then determined using conventional, Cheung and Cheung's and Norde methods.Generally, ideality factor or n values were observed to be greater than unity, which indicates the influence of some other current transport mechanism besides thermionic processes.These responses demonstrate that changes in the electrical characteristics of the metal-semiconductor-metal diode could be further utilized as sensing elements to detect alpha particles.

View Article: PubMed Central - PubMed

Affiliation: Low Dimensional Materials Research Centre (LDMRC), Department of Physics, University of Malaya, 50603 Kuala Lumpur, Malaysia. hassankirkukly@gmail.com.

ABSTRACT
Detection of nuclear radiation such as alpha particles has become an important field of research in recent history due to nuclear threats and accidents. In this context; deoxyribonucleic acid (DNA) acting as an organic semiconducting material could be utilized in a metal/semiconductor Schottky junction for detecting alpha particles. In this work we demonstrate for the first time the effect of alpha irradiation on an Al/DNA/p-Si/Al Schottky diode by investigating its current-voltage characteristics. The diodes were exposed for different periods (0-20 min) of irradiation. Various diode parameters such as ideality factor, barrier height, series resistance, Richardson constant and saturation current were then determined using conventional, Cheung and Cheung's and Norde methods. Generally, ideality factor or n values were observed to be greater than unity, which indicates the influence of some other current transport mechanism besides thermionic processes. Results indicated ideality factor variation between 9.97 and 9.57 for irradiation times between the ranges 0 to 20 min. Increase in the series resistance with increase in irradiation time was also observed when calculated using conventional and Cheung and Cheung's methods. These responses demonstrate that changes in the electrical characteristics of the metal-semiconductor-metal diode could be further utilized as sensing elements to detect alpha particles.

Show MeSH
Related in: MedlinePlus