14:15 〜 14:30
▲ [19p-234B-5] Bandgap tunable Zn3N2-Mg3N2 alloy for photovoltaic absorber
キーワード：bandgap tunability, photovoltaic absorber, Zn3N2-Mg3N2 alloy
Direct bandgap semiconductors with a bandgap energy (Eg) of ~1.4 eV are desirable for use in both photovoltaic and photocatalytic energy conversion.[1,2] Due to the fact that the semiconductors Zn3N2 and Mg3N2 have been reported to be direct-gap with Eg of 0.8[3] and 2.9 eV[4], respectively. Accordingly, the bandgap of Zn3-3xMg3xN2 can be theoretically adjusted to 1.4 eV by varying Mg content (x). Hence, In this presentation, we propose a novel nitride alloy system, Zn3-3xMg3xN2, of which bandgap is adjustable to ~1.4 eV.
Zn3-3xMg3xN2 films were deposited on YSZ (100) substrates heated at 140 ℃ by radio-frequency magnetron co-sputtering method using metal Zn and Mg targets.
XPS was adopted to determine x. Figure 1 presents optical transmittance (T) spectra for typical Zn3-3xMg3xN2 epilayers in the wavelength range of 300-3000 nm. We analyzed the transmittance and reflectance spectra using the Tauc-plot method to determine the Eg of Zn3-3xMg3xN2 (Fig. 2). This figure provides us with information that the bandgap of Zn3-3xMg3xN2 alloy system is tunable with x changing: ideal Eg ≈ 1.4 eV for photovoltaic absorber can be achieved at x = 0.18. From Hall measurements, high mobilities (µH) in alloy films with x ≤ 0.30 were obtained.
Zn3-3xMg3xN2 films were deposited on YSZ (100) substrates heated at 140 ℃ by radio-frequency magnetron co-sputtering method using metal Zn and Mg targets.
XPS was adopted to determine x. Figure 1 presents optical transmittance (T) spectra for typical Zn3-3xMg3xN2 epilayers in the wavelength range of 300-3000 nm. We analyzed the transmittance and reflectance spectra using the Tauc-plot method to determine the Eg of Zn3-3xMg3xN2 (Fig. 2). This figure provides us with information that the bandgap of Zn3-3xMg3xN2 alloy system is tunable with x changing: ideal Eg ≈ 1.4 eV for photovoltaic absorber can be achieved at x = 0.18. From Hall measurements, high mobilities (µH) in alloy films with x ≤ 0.30 were obtained.