Optical SPECTRa OF thin INTRINSIC AND AL DOPED NANOcrystalLine ZNO THIN layers DEPOSITED BY PULSED LASER DEPOSITION oN FUSED SILICA GLASS SUBSTRATEs

Zinc oxide (ZnO) is a low-cost and environmentally friendly material with unique optical properties and a variety of nano and microstructures imposing challenges for energy conversion, scintillators, photocatalytic wastewater treatment, electrochemical energy storage, or sensing applications.In this work, the nominally undoped and Al-doped nanocrystalline ZnO thin layers were pulsed laser deposited (PLD) on fused silica glass.The samples were characterized by photothermal deflection (PDS) and photoluminescence (PLS) spectroscopy.Excitons were observed at low temperature in both samples at about 3.4 eV.The intrinsic samples show the red PL in near infrared region at about 1.9 eV related to zinc vacancies.The results show that optical properties can be evaluated from optical spectra of very thin nanocrystalline ZnO layers with the thickness below 100 nm.