Bandgap tuning in ZnO thin films and enhanced n-type properties through Mn doping synthesized by a simple spray pyrolysis

2021 ◽  
pp. 2150155
Author(s):  
Md. Khorshed Alam ◽  
Mehnaz Sharmin ◽  
Jiban Podder
Keyword(s):  
Thin Films ◽  
Spray Pyrolysis ◽  
Room Temperature ◽  
Visible Region ◽  
Zno Thin Films ◽  
Bandgap Energy ◽  
Chemical Compositions ◽  
Mn Doping ◽  
X Ray ◽  
Mn Doped

Undoped and manganese (Mn)-doped zinc oxide (ZnO) thin films have been deposited onto glass substrates at 300[Formula: see text]C using a low cost spray pyrolysis technique. Structural, optical and electrical properties of the as-deposited films have been investigated. Scanning electron microscopy images show the existence of clusters with well-defined nucleation centers consisting of highly dense ganglia-like fibers over a large area around the nucleation center. Chemical compositions of the ZnO and Mn-doped ZnO thin films are studied by using energy dispersive X-ray (EDX) analysis. X-ray diffraction spectra depict that the films have polycrystalline wurtzite structure. The average crystallite sizes are calculated in the range of 8–16 nm by Williamson–Hall method and found in good agreement with Scherer method. Optical transmittance of the films is about 80% in the visible region. Bandgap energy is tuned to 2.83 eV from 3.10 eV with increasing Mn doping. Electrical resistivity at room-temperature decreases significantly with increasing Mn doping as well as increasing temperature from 300–440 K. The activation energies in the temperature ranges 300–350 K and 350–440 K are found to be in the range of 0.25–0.16 eV and 0.35–0.59 eV, respectively. Hall Effect measurements show that the thin films have negative Hall co-efficient indicating [Formula: see text]-type conductivity at room-temperature. Carrier concentration is found to be of the order of 10[Formula: see text] cm[Formula: see text].

Effects of Mn doping on electrical properties of ZnO thin films

2016 ◽  
Vol 30 (04) ◽  
pp. 1650024 ◽  
Author(s):  
Leili Motevalizadeh ◽  
Boshra Ghanbari Shohany ◽  
Majid Ebrahimizadeh Abrishami
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Spray Pyrolysis Technique ◽  
Oxygen Deficiency ◽  
Zno Thin Films ◽  
Zno Films ◽  
Mn Doping ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Mn Doped

In this paper, we have investigated the effect of Mn doping on the electrical properties of ZnO thin films. ZnO thin films with different amounts of Mn concentrations (0, 5, 10 and 15 mol.%) were prepared by spray pyrolysis technique. The crystal structure was examined by X-ray diffraction (XRD) analysis. XRD patterns showed that all the samples were crystallized in wurtzite structure while a decrease in crystallinity and switch in preferential orientations were observed in Mn-doped thin films comparing to undoped ZnO. The element composition of all thin films was detected by energy dispersive X-ray (EDX). The surface morphology of the films was investigated using field emission scanning electron microscope (FESEM) and optical properties were studied using UV-vis spectroscopy. UV-vis study revealed that the band gap blueshifts with the increase in Mn content and [Formula: see text] increases with the increase in Mn concentration. The resistivity and activation energy were measured at room temperature and ranging from 373 K to 573 K. Comparing to undoped ZnO thin film, the resistivity of Mn-doped ZnO films increased because of different parameters such as increasing barrier height energy and reducing the oxygen deficiency.

scholarly journals Synthesis and Characterisation of Thin Films of Bismuth Triiodide for Semiconductor Radiation Detectors

2014 ◽  
Vol 2014 ◽  
pp. 1-3 ◽  
Author(s):  
Alka Garg ◽  
Monika Tomar ◽  
Vinay Gupta
Keyword(s):  
Thin Films ◽  
Absorption Coefficient ◽  
Room Temperature ◽  
Active Material ◽  
Visible Region ◽  
Radiation Detectors ◽  
Radiation Absorption ◽  
X Rays ◽  
X Ray ◽  
Bismuth Iodide

Bismuth iodide is a potentially active material for room temperature radiation detector, as it is well reported in the literature that it has both wide energy band gap and high atomic absorption coefficient. Crystalline films of high atomic number and high radiation absorption coefficient can absorb the X-rays and convert them directly into electrical charges which can be read by imaging devices. Therefore, it was proposed to grow thin films of Bismuth iodide on glass substrate using thermal evaporation technique in vacuum to avoid the inclusion of impurities in the films. The structural studies of the films were carried out using XRD and optical absorption measurement was carried out in the UV/VIS region using spectrophotometer. All Bismuth iodide films grown at room temperature are polycrystalline and show X-ray diffraction peaks at angles reported in research papers. The optical transmission spectra of BiI3 films show a high transmission of about 80% in visible region with a sharp fall near the fundamental absorption at 650 nm. Resistivity of the as-grown film was found to be around 1012 ohm-cm suitable value for X-ray detection application. Films were subjected to scanning electron microscopy to study the growth features of both as-grown and annealed films.

Formation of ZnO Doped with Mn Thin Film by Electrodeposition and Magnetic Behaviour.

2005 ◽  
Vol 879 ◽  
Author(s):  
M. Abid ◽  
C. Terrier ◽  
J-P Ansermet ◽  
K. Hjort
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Room Temperature ◽  
Magnetic Behaviour ◽  
Spectroscopic Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Doped Zno ◽  
Mn Doped ◽  
Weak Ferromagnetic

AbstractFollowing the theory, ferromagnetism is predicted in Mn- doped ZnO, Indeed, ferromagnetism above room temperature was recently reported in thin films as well as in bulk samples made of this material. Here, we have prepared Mn doped ZnO by electrodeposition. The samples have been characterized by X-ray diffraction and spectroscopic methods to ensure that the dopants are substitutional. Some samples exhibit weak ferromagnetic properties at room temperature, however to be useful for spintronics this material need additional carriers provided by others means.

Electron carrier concentration dependent magnetization in ZnO:Co and ZnO:Mn thin films

2007 ◽  
Vol 1035 ◽  
Author(s):  
Zheng Yang ◽  
Maurizio Biasini ◽  
Leelaprasanna J Mandalapu ◽  
Zheng Zuo ◽  
Ward P Beyermann ◽  
...  
Keyword(s):  
Thin Films ◽  
Carrier Concentration ◽  
Concentration Dependence ◽  
Long Range ◽  
Room Temperature ◽  
Zno Thin Films ◽  
X Ray Diffraction ◽  
Electron Carrier ◽  
X Ray ◽  
Curie Temperatures

AbstractCo and Mn ions were implanted into n-type ZnO thin films with different electron carrier concentrations. X-ray diffraction measurements show that the ZnO:Co and ZnO:Mn thin films are of high crystallinity. From magnetization measurements, ferromagnetism was observed in both n-type ZnO:Co and n-type ZnO:Mn thin films with Curie temperatures well-above room temperature. Furthermore, the electron carrier concentration dependence of the saturated magnetization was measured in both types of thin films, and our results support an electron-mediated mechanism for ferromagnetism in ZnO:Co, as predicted by theory. However, our measurements seem to contradict theory for ZnO:Mn, which only predicts long-range ferromagnetism for p-type mediated material.

Thickness Dependent Room Temperature Sensing Properties of Spray Pyrolysis Deposited Nanostructured ZnO Thin Films

2015 ◽  
Vol 7 (11) ◽  
pp. 885-891 ◽  
Author(s):  
Brahmaiah Vutukuri ◽  
Ganesh Kumar Mani ◽  
Prabakaran Shankar ◽  
John Bosco Balaguru Rayappan
Keyword(s):  
Thin Films ◽  
Spray Pyrolysis ◽  
Room Temperature ◽  
Temperature Sensing ◽  
Zno Thin Films ◽  
Sensing Properties

Room Temperature Ferromagnetism and Fast Ultraviolet Photoresponse of Inkjet-Printed Mn-Doped ZnO Thin Films

2010 ◽  
Vol 46 (6) ◽  
pp. 2152-2155 ◽  
Author(s):  
Yan Wu ◽  
K. V. Rao ◽  
Wolfgang Voit ◽  
Takahiko Tamaki ◽  
O. D. Jayakumar ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Zno Thin Films ◽  
Doped Zno ◽  
Mn Doped

scholarly journals Origin of Ultraviolet Luminescence from Bulk ZnO Thin Films Grown by Molecular Beam Epitaxy

2011 ◽  
Vol 1 ◽  
pp. 135-139 ◽  
Author(s):  
M. Asghar ◽  
Khalid Mahmood ◽  
Adnan Ali ◽  
M.A. Hasan ◽  
I. Hussain ◽  
...  
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Molecular Beam Epitaxy ◽  
Room Temperature ◽  
Molecular Beam ◽  
Energy Dispersive ◽  
Zno Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Luminescence

Origin of ultraviolet (UV) luminescence from bulk ZnO has been investigated with the help of photoluminescence (PL) measurements. Thin films of ZnO having 52%, 53% and 54% of Zn-contents were prepared by means of molecular beam epitaxy (MBE). We observed a dominant UV line at 3.28 eV and a visible line centered at 2.5 eV in the PL spectrum performed at room temperature. The intensity of UV line has been found to depend upon the Zn percentage in the ZnO layers. Thereby, we correlate the UV line in our samples with the Zn-interstitials-bound exciton (Zni-X) recombination. The results obtained from, x-ray diffraction, the energy dispersive X-ray spectrum (EDAX) and Raman spectroscopy supported the PL results.

scholarly journals Growth of Zn1−x CdxO nanocrystalline thin films by sol-gel method and their characterization for optoelectronic applications

2014 ◽  
Vol 32 (4) ◽  
pp. 688-695 ◽  
Author(s):  
Munirah Munirah ◽  
Ziaul Khan ◽  
Mohd. Khan ◽  
Anver Aziz
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Visible Region ◽  
Zno Thin Films ◽  
Band Edge Emission ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cd Doping ◽  
Vis Spectroscopy ◽  
Doped Zno

AbstractThis paper describes the growth of Cd doped ZnO thin films on a glass substrate via sol-gel spin coating technique. The effect of Cd doping on ZnO thin films was investigated using X-ray diffraction (XRD), UV-Vis spectroscopy, photoluminescence spectroscopy, I–V characteristics and field emission scanning electron microscopy (FESEM). X-ray diffraction patterns showed that the films have preferred orientation along (002) plane with hexagonal wurtzite structure. The average crystallite sizes decreased from 24 nm to 9 nm, upon increasing of Cd doping. The films transmittance was found to be very high (92 to 95 %) in the visible region of solar spectrum. The optical band gap of ZnO and Cd doped ZnO thin films was calculated using the transmittance spectra and was found to be in the range of 3.30 to 2.77 eV. On increasing Cd concentration in ZnO binary system, the absorption edge of the films showed the red shifting. Photoluminescence spectra of the films showed the characteristic band edge emission centred over 377 to 448 nm. Electrical characterization revealed that the films had semiconducting and light sensitive behaviour.

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