DMSO modified PEDOT:PSS polymer/ZnO nanorods Schottky junction ultraviolet photodetector: Photoresponse, external quantum efficiency, detectivity, and responsivity augmentation using N doped graphene quantum dots

• Published in: Organic electronics Vol. 53; pp. 101 - 110
• Main Authors: Dhar, Saurab, Majumder, Tanmoy, Chakraborty, Pinak, Mondal, Suvra Prakash
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2018
• Subjects: External quantum efficiency (EQE); Nitrogen doped graphene quantum dots; PEDOT:PSS; Schottky junction UV detector; ZnO nanorods; ZnO nanorods; Schottky junction UV detector; Nitrogen doped graphene quantum dots; External quantum efficiency (EQE); PEDOT:PSS
• ISSN: 1566-1199; 1878-5530
• DOI: 10.1016/j.orgel.2017.11.024

Schottky junction ultraviolet (UV) photodetector was fabricated by spin coating a hole conducting polymer, poly 3,4-ethylenedioxythiophene: polystyrene sulfonate (PEDOT:PSS) on hydrothermally grown zinc oxide (ZnO) nanorod array. The photodetector performance was improved by increasing the conductivity of PEDOT:PSS polymer using dimethyl sulfoxide (DMSO) additive. The UV detector performance was further enhanced significantly by sensitizing ZnO nanorods with N doped graphene quantum dots (NGQDs). NGQD decorated ZnO NRs/DMSO-PEDOT:PSS Schottky junction device demonstrated superior external quantum efficiency (EQE ∼ 90063%), responsivity (Rλ∼247 A/W) and detectivity (Dλ∼2.42 × 1011 Hz1/2/W) at 340 nm wavelength and –1V external bias. The EQE of NGQD modified sample was 56 times higher than pristine PEDOT:PSS/ZnO NR and 4.3 times higher than DMSO modified PEDOT:PSS/ZnO NRs device. NGQD sensitized detector showed superior photocurrent of 80.77 mA/cm2 at 340 nm wavelength, –1V external bias, which was 2 times higher than DMSO modified and 32 times higher than pristine PEDOT:PSS based device. The photocurrent rise and decay time of NGQD sensitized NRs are very fast compared to other photodetectors. [Display omitted] •UV photodetectors were fabricated using ZnO nanorods and DMSO modified PEDOT:PSS.•Detector performance was boosted by using N doped graphene quantum dots (NGQDs).•NGQDs sensitized detectors demonstrated superior EQE, responsivity and detectivity.•The photocurrent rise and decay time were also improved after NGQDs attachment.