Effects of Mg x Zn1- x O Thickness on the Bandwidth of Metal–Semiconductor–Metal Bandpass Photodetectors
| Autor: | Guan-Syun Lin, Sheng-Beng Hwang, Jun-Dar Hwang |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Photon business.industry Bilayer Photodetector chemistry.chemical_element 02 engineering and technology Zinc 021001 nanoscience & nanotechnology 01 natural sciences Electronic Optical and Magnetic Materials Metal Wavelength chemistry visual_art 0103 physical sciences visual_art.visual_art_medium Optoelectronics Electrical and Electronic Engineering Photonics 0210 nano-technology business Photonic crystal |
| Zdroj: | IEEE Transactions on Electron Devices. 64:195-199 |
| ISSN: | 1557-9646 0018-9383 |
| DOI: | 10.1109/ted.2016.2628727 |
| Popis: | A metal–semiconductor–metal photodetector (PD) whose detection wavelength can be modulated was fabricated using a Mg x Zn1- x O/ZnO bilayer. By varying the Mg x Zn1- x O layer thickness (50–400 nm), we modulated the detection wavelength from lowpass to bandpass. For a thin (50 nm) Mg x Zn1- x O film, most short-wavelength (less than 340 nm) incident photons—more than 69%—passed through the Mg x Zn1- x O and were absorbed by ZnO, causing a higher photoresponse in the short-wavelength region and thus a low-pass PD. As the thickness of the Mg x Zn1- x O film increased, the short-wavelength photoresponse was gradually suppressed, and a bandpass PD was achieved. A thicker (400 nm) Mg x Zn1- x O film absorbed more short-wavelength (less than 340 nm) incident photons, leaving only 5.5% of the incident photons to be absorbed by the ZnO layer underneath. This reduced the short-wavelength photoresponse, yielding a bandpass PD with a detection wavelength of 325–360 nm. Although the short-wavelength (less than 340 nm) incident photons were absorbed by Mg x Zn1- x O, few photogenerated electron–hole pairs contributed to the photoresponse; instead, they were trapped by the defects in Mg x Zn1- x O because of its poor crystalline quality. |
| Databáze: | OpenAIRE |
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