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Highly tolerant diamond Schottky barrier photodiodes for deep-ultraviolet xenon excimer lamp and protons detection

Masataka Imura,Manabu Togawa,Masaya Miyahara,Hironori Okumura,Jiro Nishinaga,Meiyong Liao,Yasuo Koide
Volume 2, Issue 1 (2022)
DOI: 10.1080/26941112.2022.2150526


The response property and stability of diamond Schottky barrier photodiodes (SBPDs) were investigated for the monitor applications of deep ultraviolet (DUV) light and high-energy radiation particles. The SBPDs were fabricated on the unintentionally doped insulating diamond epilayer grown on a heavily boron-doped p+-diamond (100) conductive substrate by microwave plasma chemical vapor deposition. The vertical-type SBPDs were constructed of semitransparent tungsten carbide (WC) Schottky contact on the top of the device and a WC/titanium ohmic contact on the bottom. The SBPDs were operated to detect the DUV light and protons in zero-bias photovoltaic mode. The spectral response of the SBPDs showed that the peak wavelength was at 182 nm with a sensitivity of 46 ± 1 mA/W. The response speed was shorter than 1 sec, with a negligible charge-up effect and persistent photoconductivity. The SBPDs showed a stable response upon the irradiation by 172-nm xenon excimer lamp with 70 mW/cm2 for 200 hrs and 70 MeV protons for the dose of 10 MGy, corresponding to a non-ionizing energy loss of 1.4 × 1016 MeV neq/cm2.


diamond; Schottky barrier photodiode; deep-ultraviolet light; detector for xenon excimer lamp; detector for protons


  • Roberts RA, Walker WC. Optical study of the ­electronic structure of diamond. Phys. Rev. 1967;161(3):730–735.
  • Nahum J, Halperin A. Excitation spectra and temperature dependence of luminescence and photoconductivity of diamond. J Phys Chem Solids. 1962;23(4):345–358.
  • Binari SC, Marchywka M, Koolbeck DA, et al. Diamond metal-semiconductor-metal ultraviolet photodetectors. Diamond Related Mater. 1993;2(5-7):1020–1023.
  • Vaitkus R, Inushima T, Yamazaki S. Enhancement of photosensitivity by ultraviolet irradiation and photoconductivity spectra of diamond thin films. Appl Phys Lett. 1993;62(19):2384–2386.
  • Mckeag RD, Chan SSM, Jackman RB. Polycrystalline diamond photoconductive device with high UV‐visible discrimination. Appl Phys Lett. 1995;67(15):2117–2119.
  • BenMoussa A, Schuhle U, Haenen K, et al. PIN diamond detector development for LYRA, the solar VUV radiometer on board PROBA II. Phys Stat Sol (a). 2004;201(11):2536–2541.
  • Teraji T, Yoshizaki S, Wada H, et al. Highly sensitive UV photodetectors fabricated using high-quality single-crystalline CVD diamond films. Diamond Rel Mater. 2004;13(4-8):858–862.
  • Remes Z, Petersen R, Haenen K, et al. Mechanism of photoconductivity in intrinsic epitaxial CVD diamond studied by photocurrent spectroscopy and photocurrent decay measurements. Diamond Relat Mater. 2005;14(3-7):556–560.
  • Balducci A, Marinelli M, Milani E, et al. Extreme ultraviolet single-crystal diamond detectors by chemical vapor deposition. Appl Phys Lett. 2005;86(19):193509.
  • Lin CN, Lu YJ, Yang X, et al. Diamond-based all-carbon photodetectors for solar-blind imaging. Adv Opt Mater. 2018;6(15):1800068.
  • Lin CN, Zhang ZF, Lu YJ, et al. High performance diamond-based solar-blind photodetectors enabled by Schottky barrier modulation. Carbon. 2022;200:510–516.
  • Wei MS, Yao KY, Liu YM, et al. A solar-blind UV detector based on graphene-microcrystalline diamond heterojunctions. Small. 2017;13(34):1701328.
  • Chen YC, Lu YJ, Lin CN, et al. Self-powered diamond/β-Ga2O3 photodetectors for solar-blind imaging. J Mater Chem C. 2018;6(21):5727–5732.
  • Bauer C, Baumann I, Colledani C, et al. Recent results from the RD42 diamond detector collaboration. Nuclear Instruments Methods Phys Res Sec A Accelerators Spectrometers Detectors Assoc Equip. 1996;383(1):64–74.
  • Muskinja M, Cindro V, Gorisek A, et al. Investigation of charge multiplication in single crystalline CVD diamond particle detectors. Nuclear Instruments Methods Phys Res Sect A Accel Spectr Detectors Assoc Equip. 2017;841:162–169.
  • Bani L, Alexopoulos A, Artuso M, Unno and RD42 Collaboration, et al. A study of the radiation tolerance of CVD diamond to 70 MeV protons, fast neutrons and 200 MeV pions. Sensors. 2020;20(22):6648.
  • Alvarez J, Liao MY, Koide Y. Large deep-ultraviolet photocurrent in metal-semiconductor-metal structures fabricated on as-grown boron-doped diamond. Appl Phys Lett. 2005;87(11):113507.
  • Liao MY, Sang LW, Teraji T, et al. Comprehensive investigation of single crystal diamond Deep-Ultraviolet detectors. Jpn J Appl Phys. 2012;51(9R):090115.
  • Liao MY, Alvarez J, Koide Y. Thermal stability of diamond photodiodes using tungsten carbide as Schottky contact. Jpn J Appl Phys. 2005;44(11):7832–7838.
  • Liao MY, Koide Y, Alvarez J. Thermally stable visible-blind diamond photodiode using tungsten carbide Schottky contact. Appl Phys Lett. 2005;87(2):022105.
  • Liao MY, Koide Y, Alvarez J. Single Schottky-barrier photodiode with interdigitated-finger geometry: application to diamond. Appl Phys Lett. 2007;90(12):123507.
  • Liao MY, Koide Y, Alvarez J, et al. Persistent positive and transient absolute negative photoconductivity observed in diamond photodetectors. Phys Rev B. 2008;78(4):045112.
  • Imura M, Koide Y, Liao MY, et al. Vertical-type Schottky-barrier photodiode using p-diamond epilayer grown on heavily boron-doped p+-diamond substrate. Diamond Relat Mater. 2008;17(11):1916–1921.
  • Imura M, Liao MY, Alvarez J, et al. Schottky-barrier photodiode using p-diamond epilayer grown on p+-diamond substrates. Diamond Relat Mater. 2009;18(2-3):296–298.
  • Bormashov VS, Tarelkin SA, Buga SG, et al. Electrical properties of the high quality boron-doped synthetic single-crystal diamonds grown by the temperature gradient method. Diamond Relat Mater. 2013;35:19–23.
  • Teraji T, Fiori A, Kiritani N, et al. Mechanism of reverse current increase of vertical-type diamond Schottky diodes. J Appl Phys. 2017;122(13):135304.
  • Fewster PF, Andrew NL. Absolute lattice-parameter measurement. J Appl Crystallogr. 1995;28(4):451–458.
  • Liao M. Progress in semiconductor diamond photodetectors and MEMS sensors. Functional Diamond. 2021;1(1):29–46.
  • Agostinelli S, Allison J, Amako K, et al. Geant4—a simulation toolkit. Nuclear Instr Methods Phys Res Sec A Accel Spectrom Detect Assoc Equip. 2003;506(3):250–303.
  • Allison J, Amako K, Apostolakis J, et al. Geant4 developments and applications. IEEE Trans. Nucl. Sci. 2006;53(1):270–278.
  • Allison J, Amako K, Apostolakis J, et al. Recent developments in Geant4. Nuclear Instruments Methods Phys Res Sect A Accel Spectr Detectors Assoc Equip. 2016;835:186–225.
  • Schlesinger TE, James RB. Chapter 8: CdTe Nuclear Detectors and Applications. In: Hage-Ali M, Siffert P, editor. Semiconductors for room temperature nuclear detector applications. London, UK: Academic Press; 1995. pp. 43.
  • Shikata S, Tanno T, Teraji T, et al. Precise measurements of diamond lattice constant using bond method. Jpn J Appl Phys. 2018;57(11):111301.
  • Brazhkin VV, Ekimov EA, Lyapin AG, et al. Lattice parameters and thermal expansion of superconducting boron-doped diamonds. Phys Rev B. 2006;74(14):140502.
  • Brunet F, Germi P, Pernet M, et al. The effect of boron doping on the lattice parameter of homoepitaxial diamond films. Diamond Relat Mater. 1998;7(6):869–873.
  • Solin SA, Ramdas AK. Raman spectrum of diamond. Phys Rev B. 1970;1(4):1687–1698.
  • Padovani FA, Stratton R. Field and thermionic-field emission in Schottky barriers. Solid-State Electron. 1966;9(7):695–707.
  • Umezawa H, Tokuda N, Ogura M, et al. Characterization of leakage current on diamond Schottky barrier diodes using thermionic-field emission modeling. Diamond Relat Mater. 2006;15(11-12):1949–1953.
  • Srimongkon K, Ohmagari S, Kato Y, et al. Boron inhomogeneity of HPHT-grown single-crystal diamond substrates: confocal micro-Raman mapping investigations. Diamond and Related Materials. 2016;63:21–25.
  • Liao MY, Koide Y, Alvarez J. Photovoltaic Schottky ultraviolet detectors fabricated on boron-doped homoepitaxial diamond layer. Appl Phys Lett. 2006;88(3):033504.
  • Kamiya T, Narushima S, Mizoguchi H, et al. Electrical properties and structure of p-Type amorphous oxide SemiconductorxZnO·Rh2O3. Adv Funct Mater. 2005;15(6):968–974.
  • Teraji T, Koizumi S, Koide Y, et al. Electric field breakdown of lateral Schottky diodes of diamond. Jpn J Appl Phys. 2007;46(9):L196–L198.
  • Suda J, Yamaji K, Hayashi Y, et al. Nearly ideal current–voltage characteristics of Schottky barrier diodes formed on hydride-vapor-phase-epitaxy-grown GaN free-standing substrates. Appl Phys Express. 2010;3(10):101003.
  • Schroeder H. Poole-Frenkel-effect as dominating current mechanism in thin oxide films—an illusion?! J Appl Phy . 2015;117(21):215103.

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