| 학회 | 한국재료학회 |
| 학술대회 | 2018년 가을 (11/07 ~ 11/09, 여수 디오션리조트) |
| 권호 | 24권 2호 |
| 발표분야 | H. 한-일 재료공학(KJMST 2018) |
| 제목 | Ecofriendly Mg2Si-based-photodiode for IR sensor applications |
| 초록 | IR sensors have long been employed in diverse military and commercial applications such as enhancing automobile and aircraft safety, quality control in industrial processes as well as medical diagnosis. Alas, those IR sensors are mainly constructed from InGaAs, HgCdTe and InSb whose constituents are extremely toxic and present in nature in very rare amount. Recently, IR light detection using cost-effective, non-toxic and naturally abundant semiconducting silicides has attracted increasing area of pursuit in research. Mg2Si is one of those eco-friendly silicides that could be implemented for IR sensation due to the following causes. It has a narrow band gap, around 0.7 eV, a value that can be easily engineered to 0.3 eV by alloying with Mg2Sn. Besides that, it has a small lattice mismatch with Si (＜ 2%) and high absorption coefficient near its absorption edge, along with affordability, non-toxicity and abundance of its constituents. Despite all these distinctive properties of Mg2Si for IR sensation, there are few reports about the photoresponse of Mg2Si Schottky and pn-junction diodes. Herein, we designed that work, firstly to grow high purity Mg2Si single crystal, secondly to fabricate Mg2Si Schottky and pn-junction diodes, and finally to check the photoresponse characteristics for the fabricated diodes. XRD proved that the grown crystal consists of only Mg2Si single phase. The clear Laue symmetrical diffraction pattern demonstrated the single crystalline nature of the grown crystal. Hall Effect measurements revealed a moderate carrier density (~1016 cm-3), mobility (~ 446 cm2/Vs), and electrical resistivity (~ 1.4 Ω. cm) for the grown crystal. We have determined the nature of contact between different metals and n-Mg2Si substrate. All the measured metal/n-Mg2Si contacts showed an Ohmic property except for the Au/n-Mg2Si contact that demonstrated a clear Schottky property. Among the measured Ohmic contacts, Al/n-Mg2Si showed the best Ohmic property with the lowest contact resistance. The fabricated Schottky and Mg2Si pn-junction diodes showed a clear diode behavior with high rectification ratio. Furthermore, Mg2Si diode demonstrated a clear photoresponse characteristics in the short-wavelength IR light region from 0.95 to 1.8μm, demonstrating its significance to detect the IR illumination in that wavelength domain. This work has been partially supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) Element Strategy Initiative to Form Core Center of Japan. |
| 저자 | Ahmed ELAMIR1, Takeo OHSAWA2, Masaru NAKAMURA3, Kiyoshi SHIMAMURA4, Naoki OHASHI5 |
| 소속 | 1Optical Single Crystals Group, 2NIMS, 31-1 Namiki, 4Tsukuba, 5Ibaraki |
| 키워드 | Mg<SUB>2</SUB>Si single crystal; Schottky contact; Ohmic contact; IR detector <BR><BR> |
