Surface modification of ZnO nanorods with CdS quantum dots for application in inverted organic solar cells: effect of deposition duration

• Published in: Journal of materials science. Materials in electronics 2018-02, Vol.29 (4), p.2601-2609
• Main Authors: Oleiwi, Hind Fadhil, Zakaria, Azmi, Yap, Chi Chin, Tan, Sin Tee, Lee, Hock Beng, Tan, Chun Hui, Ginting, Riski Titian, Alshanableh, Abdelelah, Talib, Zainal Abidin
• Format: Article
• Language: English
• Subjects: Cadmium sulfide; Carrier recombination; Characterization and Evaluation of Materials; Chemistry and Materials Science; Current carriers; Defects; Deposition; Devices; Electron traps; Magnetron sputtering; Materials Science; Nanorods; Open circuit voltage; Optical and Electronic Materials; Optical properties; Optoelectronic devices; Photovoltaic cells; Quantum dots; Short circuits; Solar cells; Substrates; Zinc oxide
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-017-8185-7

Incorporating cadmium sulfide quantum dots (CdS QDs) onto ZnO nanorod (ZNRs) has been investigated to be an efficient approach to enhance the photovoltaic performance of the inverted organic solar cell (IOSC) devices based on ZNRs/poly (3-hexylthiophene) (P3HT). To synthesize CdS/ZNRs, different durations of deposition per cycle from 1 to 9 min were used to deposit CdS via SILAR technique onto ZNRs surface grown via hydrothermal method at low temperature on FTO substrate. In typical procedures, P3HT as donor polymer were spun-coating onto CdS/ZNRs to fabricate IOSC devices, followed by Ag deposition as anode by magnetron sputtering technique. Incorporation of CdS QDs has modified the morphological, structural, and optical properties of ZNRs. Incorporation of CdS QDs onto ZNRs also led to higher open circuit voltage (V oc ) and short circuit current density (J sc ) of optimum ZNRs/CdS QDs devices due to the increased interfacial area between ZNRs and P3HT for more efficient exciton dissociation, reduced interfacial charge carrier recombination as a result of lower number of oxygen defects which act as electron traps in ZnO and prolonged carrier recombination lifetime. Therefore, the ZNRs/CdS QDs/P3HT device exhibited threefold higher PCE (0.55%) at 5 min in comparison to pristine ZNR constructed device (0.16%). Overall, our study highlights the potential of ZNRs/CdS QDs to be excellent electron acceptors for high efficiency hybrid optoelectronic devices.