High-performance ultraviolet detection and visible-blind photodetector based on Cu2O/ZnO nanorods with poly-(N -vinylcarbazole) intermediate layer

Dung Ching Perng, Hsueh Pin Lin, Min Hao Hong

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Abstract

This study reports a high-performance hybrid ultraviolet (UV) photodetector with visible-blind sensitivity fabricated by inserting a poly-(N-vinylcarbazole) (PVK) intermediate layer between low-cost processed Cu2O film and ZnO nanorods (NRs). The PVK layer acts as an electron-blocking/hole-transporting layer between the n-ZnO and p-Cu2O films. The Cu2O/PVK/ZnO NR photodetector exhibited a responsivity of 13.28 A/W at 360 nm, a high detectivity of 1.03 × 1013 Jones at a low bias of -0.1 V under a low UV light intensity of 24.9 μW/cm2. The photo-to-dark current ratios of the photodetector with and without the PVK intermediate layer at a bias of -0.5 V are 1.34 × 102 and 3.99, respectively. The UV-to-visible rejection ratios (R360 nm/R450 nm) are 350 and 1.735, respectively. Several features are demonstrated: (a) UV photo-generated holes at the ZnO NRs can effectively be transported through the PVK layer to the p-Cu2O layer; (b) the insertion of a PVK buffer layer significantly minimizes the reverse-bias leakage current, which leads to a larger amplification of the photocurrent; and (c) the PVK buffer layer greatly improves the UV-to-visible responsivity ratio, allowing the device to achieve high UV detection sensitivity at a low bias voltage using a very low light intensity.

Original languageEnglish
Article number241113
JournalApplied Physics Letters
Volume107
Issue number24
DOIs
Publication statusPublished - 2015 Dec 14

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All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

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