High responsivity solar blind photodetector based on high Mg content MgZnO film grown via pulsed metal organic chemical vapor deposition

Abstract

Metal-semiconductor-metal (MSM) structured solar blind photodetectors were fabricated based on various Mg content wurtzite Mg x Zn 1-x O epitaxial films grown via pulsed metal organic chemical vapor deposition. The response spectra of the devices showed a peak position that shifts from ~383 nm to 276 nm for Mg content, x, between 0.0 and 0.51, covering a wide portion of the ultraviolet spectral region, extending well into the solar blind window. At 10 V bias, a large responsivity of ~1.8x10 4 A/W was obtained at 276 nm for a device based on a high Mg content (x=0.51) MgZnO film. To the best of our knowledge, this responsivity is the highest ever reported for a MgZnO based device and its origin is attributed to large internal gain resulting from carrier trapping at the MgZnO/Ni/Au interface. This is confirmed by the presence of an asymmetric Schottky barrier height on the two MSM contacts. Conversely, the response speed of the devices was slow with the 10%-90% rise and fall times measured to be in the millisecond range. The results reported in this work show the realization of high responsivity MgZnO based solar blind photodetectors, providing a significant step in the development of MgZnO alloy based of detector.

Recent Progress in Solar‐Blind Deep‐Ultraviolet Photodetectors Based on Inorganic Ultrawide Bandgap Semiconductors

“…As a supplement to photoconductors, MSM photodetectors based on Mg x Zn 1− x O films have also received wide research interest . To overcome phase separation in Mg x Zn 1− x O films with high Mg content, some strategies have been developed such as using a ZnO buffer layer during MBE growth or adopting relatively high substrate temperature and low growth rate during magnetron sputtering .…”

“…As a supplement to photoconductors, MSM photodetectors based on Mg x Zn 1−x O films have also received wide research interest. [149][150][151][152][153][154][155][156][157][158][159] To overcome phase separation in Mg x Zn 1−x O films with high Mg content, some strategies have been developed such as using a ZnO buffer layer during MBE growth or adopting relatively high substrate temperature and low growth rate during magnetron sputtering. [149,150] MSM photodetectors made from single-phase h-Mg 0.46 Zn 0.54 O films showed peak responsivity of 31.1 A W −1 at 70 V bias with a cutoff wavelength of 280 nm and an internal gain of 148.…”

Avalanche Effect and High External Quantum Efficiency in MgZnO/Au/ZnO Sandwich Structure Photodetector

“…The phase separation of MgZnO was avoided that often happens in high component Mg of MgZnO. [17,18] Figure 2a illustrates that for SSPD, the diffraction intensity of w-MgZnO increases. The diffraction angle of (002) peak gets shifted from 35.16° to 34.98°.…”

Annealing effect on the physical properties of TiO2 thin films deposited by spray pyrolysis

“…26 The uniformity and quality of TiO 2 thin films depend on the deposition technique. There are several well-established physical and chemical techniques listed in the literature to deposit TiO 2 thin films such as RF sputtering, 27 pulsed laser deposition (PLD), 28 metal–organic chemical vapor deposition (MOCVD), 29 spray pyrolysis 30 and sol–gel. 31…”