Materials - Policrystalline layer of zinc oxide

Policrystalline layer of zinc oxide


Zinc oxide (ZnO) thin films are obtained by atomic layer deposition (ALD) on many substrates, like Si, GaN, SiC, Al2O3 SiO2 etc. The material is formed in a double exchange chemical  reaction between two reactants (precursors), such as a deionized water (oxygen precursor) and a diethylzinc - DEZ (zinc precursor). The use of a ammonia water (NH3۰H2O) instead of deionized water as a oxide precursor in a growth process increases the electrical resistance of zinc oxide layers. ZnO can be grown at the temperature range from 25°C to 300°C. The maximum size of the substrate is 20 cm of a diameter.



  • Thickness: 10 - 3000 nm
  • Growth rate: 0.4 nm/min
  • Mobility carrier: 2 - 30 cm2/Vs
  • Concentration carrier: <1020 cm-3
  • Resistivity: 0.001 - 109Ωcm
  • Carrier type: n
  • Energy gap: 3.4 eV
  • Refractive index: 1.9 (635 nm)
  • Surface roughness: 1 nm < RMS < 30 nm
  • Crystal structure: wurtzite in hexagonal phase
  • Average transmission in visible spectra:> 80%
  • Uniformity of coatings



ZnO is semiconductor material, which is investigated for many possible applications in electronics, optoelectronics and photovoltaics. Physical and chemical properties of ZnO give us a great possibility of use of this material in devices, such as display panels, light emitting diodes or solar cells. Due to a wide band gap, ZnO is a transparent material in the visible range, so it can successfully be used in the so-called. "transparent electronics." Simultaneously, ZnO has a very high sensitivity and thermal stability, which makes it suitable for applications in sensor devices.


Uniformity of zinc oxide layer deposited on 11 cm diameter silicon substrate.

Cross-section SEM image and surface AFM scan of ZnO layer with 100 nm thickness deposited at 150 ° C on silicon substrate.

X-ray diffraction pattern (XRD) of the ZnO layer with 1 µm thickness grown at 200°C on a glass substrate.