Font Size: a A A

The Fabrication And Characterization Of MgZnO Thin Films And MgZnO Based Ultraviolet Detectors

Posted on:2012-10-24Degree:DoctorType:Dissertation
Country:ChinaCandidate:S HanFull Text:PDF
GTID:1118330368995727Subject:Condensed matter physics
Abstract/Summary:PDF Full Text Request
MgZnO material has many advantages, such as: no Toxicity, no pollution to environment, wide band gap adjustable region, has lattice matched substrate , so in recent years the fabrication of MgZnO Materials and MgZnO based UV detectors has become a hotspot. In this thesis, hexagonal and cubic structure MgZnO thin films would be grown by reactive magnetron sputtering and metal organic chemical vapor deposition (MOCVD) methods, and the prorperties of MgZnO and its application in UV detectors would be studied. The main contents are as follows:[1] Hexagonal orientation Mg0.53Zn0.47O thin films were prepared on quartz and c-plane sapphire substrate by multi-target reactive magnetron sputtering method. And UV detectors with detectable wavelength range from 270-320nm were fabricated on prepared Mg0.53Zn0.47O thin films. The study on effect of different substrates on light absorption and UV response characteristics of MgZnO thin films was carried out.[2]Cubic structure MgZnO thin films with different Mg composition were prepared on fused quartz substrates by the method of reactive magnetron sputtering, the crystallization and optical properties of cubic MgZnO thin films were studied. Under optimal growth conditions, cubic MgZnO thin films were prepared on different plane sapphire substrates. The Effect of different annealing temperature on crystal quality, surface morphology, and absorption spectra properties of cubic MgZnO on different plane sapphire substrates was studied.[3] Through introducing a MgO buffer layer, slick surface Mg0.58Zn0.42O thin film on lattice matched single crystal MgO substrates by MOCVD method. And MSM structure solar-blind UV detector was fabricated on prepared high quality Mg0.58Zn0.42O with response peak at 240nm, cut-off response edge at 255nm. The effect of MgO buffer layer on crystal quality, surface morphology, absorption spectrum and other properties of cubic MgZnO thin films were studied. Under optimized growth conditions, high quality single crystal cubicMgZnO film was prepared on MgO substrate, and solar-blind photoconductive UV detector was fabricated on the MgZnO thin film By wet etching method with internal gain. At bias voltage over 15V bias, the quantum efficiency of the device at 238nm is more than 100%.[4] For the first time, Au/Mg0.27Zn0.73O/In Schottky photovoltaic detector was fabricated by a two-step anneal treatment method. Under -5V bias voltage, visible responsivity of the detector is about an order of magnitude smaller than the detector on as-grown MgZnO thin film. By surface morphology and photoluminescence measurements, the reason for the improvement of the contact characteristics between the Au electrode and the MgZnO is discussed.
Keywords/Search Tags:reactive multi-target magnetron sputtering, MgZnO, ultraviolet detectors, Schottky contact
PDF Full Text Request
Related items