Synergistic enhancement in the microelectronic properties of poly-(dioctylfluorene) based Schottky devices by CdSe quantum dots

Muhammad, F., Tahir, M., Zeb, M., Kalasad, M. N., Mohd Said, S., Sarker, M. R., Sabri, M. F. M. and Ali, S. H. M. (2020) Synergistic enhancement in the microelectronic properties of poly-(dioctylfluorene) based Schottky devices by CdSe quantum dots. Scientific Reports, 10, 4828. (doi: 10.1038/s41598-020-61602-1) (PMID:32179797) (PMCID:PMC7075892)

Abstract

This paper reports the potential application of cadmium selenide (CdSe) quantum dots (QDs) in improving the microelectronic characteristics of Schottky barrier diode (SBD) prepared from a semiconducting material poly-(9,9-dioctylfluorene) (F8). Two SBDs, Ag/F8/P3HT/ITO and Ag/F8-CdSe QDs/P3HT/ITO, are fabricated by spin coating a 10 wt% solution of F8 in chloroform and 10:1 wt% solution of F8:CdSe QDs, respectively, on a pre-deposited poly(3-hexylthiophene) (P3HT) on indium tin oxide (ITO) substrate. To study the electronic properties of the fabricated devices, current-voltage (I-V) measurements are carried out at 25 °C in dark conditions. The I-V curves of Ag/F8/P3HT/ITO and Ag/F8-CdSe QDs/P3HT/ITO SBDs demonstrate asymmetrical behavior with forward bias current rectification ratio (RR) of 7.42 ± 0.02 and 142 ± 0.02, respectively, at ± 3.5 V which confirm the formation of depletion region. Other key parameters which govern microelectronic properties of the fabricated devices such as charge carrier mobility (µ), barrier height (ϕ ), series resistance (R ) and quality factor (n) are extracted from their corresponding I-V characteristics. Norde's and Cheung functions are also applied to characterize the devices to study consistency in various parameters. Significant improvement is found in the values of R , n, and RR by 3, 1.7, and 19 times, respectively, for Ag/F8-CdSe QDs/P3HT/ITO SBD as compared to Ag/F8/P3HT/ITO. This enhancement is due to the incorporation of CdSe QDs having 3-dimensional quantum confinement and large surface-to-volume area. Poole-Frenkle and Richardson-Schottky conduction mechanisms are also discussed for both of the devices. Morphology, optical bandgap (1.88 ± 0.5 eV) and photoluminescence (PL) spectrum of CdSe QDs with a peak intensity at 556 nm are also reported and discussed.

• Item Type: Articles

Additional Information

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er Education Commission, Pakistan for the grant (Project No. 10170/KPK/ NRPU/R&D
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• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Muhammad, Fida
• Authors: Muhammad, F., Tahir, M., Zeb, M., Kalasad, M. N., Mohd Said, S., Sarker, M. R., Sabri, M. F. M., and Ali, S. H. M.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Scientific Reports
• Publisher: Nature Research
• ISSN: 2045-2322
• ISSN (Online): 2045-2322
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in Scientific Reports 10: 4828
• Publisher Policy: Reproduced under a Creative Commons License