Acid-Treated PEDOT:PSS Polymer and TiO 2 Nanorod Schottky Junction Ultraviolet Photodetectors with Ultrahigh External Quantum Efficiency, Detectivity, and Responsivity

• Published in: ACS applied materials & interfaces 2018-12, Vol.10 (48), p.41618-41626
• Main Authors: Dhar, Saurab, Chakraborty, Pinak, Majumder, Tanmoy, Mondal, Suvra Prakash
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.8b12643

Vertically aligned TiO nanorods (NRs) were synthesized on a fluorine-doped tin oxide-deposited glass substrate by the hydrothermal method. A Schottky junction ultraviolet photodetector was fabricated by spin-coating of the poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) polymer on TiO NRs. For the improvement of device performance, the electrical conductivity of the polymer was increased by adding dimethyl sulfoxide (DMSO) and concentrated H SO acid. The diode parameters, i.e., work function, series resistance, and ideality factor, were studied for all devices. Photoresponse behavior of the TiO nanorod/PEDOT:PSS junction was studied upon illumination of white light of intensity 80 mW/cm . Our acid-treated sample demonstrated the highest photocurrent value, which is 10 times larger than that of DMSO-treated and 39 times larger than that of the untreated sample. Our acid-treated device showed superior external quantum efficiency (∼12 560%), responsivity (∼34.43 A/W), and detectivity (∼1.6 × 10 Hz /W) at ∼340 nm wavelength under -1 V bias.