Seminar LMGP - 19/11/2019 - Punam MURKUTE

Emerging Material Zinc Magnesium Oxide: Growth, Synthesis And High Sensitive Device Applications
Punam Murkute
Post-doc / LMGP

Abstract
Oxide based semiconductors are of significant importance as they can be utilized in various opto-electronic device applications. Amongst these oxide semiconductors, ZnO has gained particular attention due to its wide band gap (3.37 eV), high exciton binding energy (60 meV) at room temperature and band gap tunability. A cost-effective RF sputtering technique was employed to realize high quality ZnO and Zn1-xMgxO thin films and a post growth annealing treatment was performed on the best obtained RF sputtered thin film to further improve its opto-electrical and structural properties. A low-cost and unique hydrothermal bath process was utilized to realize high quality Zn1-xMgxO nanorods using the optimized RF sputtered seed layer. These Zn1-xMgxO nanorods are utilized in various device applications like photodetectors and ionic current based humidity sensor. The highlight of this work is to establish superiority of ternary alloy (Zinc magnesium oxide) over Zinc oxide in terms of optical, structural, elemental and various device applications. Enhancement in optical and crystalline quality was observed from photoluminescence, high resolution transmission electron microscopy, and high resolution X-ray diffraction spectra. A state of art peak responsivity of 62.19 A/W at around 350 nm attributed to near band edge emission peak and approximately two order of enhancement in current density was measured from Zn1-xMgxO nanorods based photo detector. Proposed Zn1-xMgxO nanorods based detector exhibited temporal response with reasonable rise and fall time constants along with three order higher detectivity values in comparison to ZnO nanorods based detector. Optical and electrical characteristics dependence on humidity is discussed in detail in this work. AC based impedance measurement on Zn1-xMgxO based sensor exhibited high sensitivity of 1.503%/RH for change in relative humidity (RH). Zn1-xMgxO based nanostructure proved that the devices fabricated from our proposed nanostructure had higher efficiency in terms of current, sensitivity, repeatability, and area of operability (i.e. better linearity with relative humidity) when compared with ZnO nanorods based humidity sensor.

Date infos
Grenoble INP - Phelma
3 parvis Louis Néel - 38000 Grenoble
Accès : TRAM B arrêt Cité internationale
Location infos
2:00 pm - Seminar room LMGP - second floor