MgZnO MSM UV Photodetector with Different Annealing Temperatures by RF Magnetron Sputtering

J. S. Jheng, C. K. Wang, Y. Z. Chiou, S. P. Chang, S. J. Chang

Research output: Contribution to journalArticlepeer-review

Abstract

We investigated the MgZnO metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector (PD) with different annealing temperatures grown by RF magnetron sputter. The MgZnO MSM PD at an annealing temperature of 700 °C has the lowest dark-current and the highest photo-to dark-current ratio (PDRC), which are 5.93 × 10-11 and 5.69 × 104 A at a bias voltage of-5 V, respectively. Higher annealing temperature improves the dark-current due to less grain boundary and number of oxygen vacancies (Ov). The PD without annealing process has the highest responsivity of 0.189 A W-1, and the external quantum efficiency (EQE) achieves to 63.3% due to the persistent photoconductivity (PPC) effect. However, a massive number of interface defects provide a leakage path for dark-current that reduces the responsivity ratio of ultraviolet to visible light (RUV peak/R440 nm). Conversely, the responsivity ratio of ultraviolet to visible light of MgZnO MSM PD annealed at 700 °C achieves to 9.83 due to high crystal quality. Finally, the device using MgZnO target material with 20% Mg content keeps a Mg content of 14.2% at an annealing temperature of 700 °C higher than the as-grown device (only Mg content of 6.2%).

Original languageEnglish
Article number055015
JournalECS Journal of Solid State Science and Technology
Volume9
Issue number5
DOIs
Publication statusPublished - 2020 Jan 6

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials

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