scholarly journals The dielectric functions and optical band gaps of thin films of amorphous and cubic crystalline Mg~2NiH~4

2012 ◽  
Vol 520 (22) ◽  
pp. 6786-6792 ◽  
Author(s):  
J.H. Selj ◽  
T. Mongstad ◽  
B.C. Hauback ◽  
S.Zh. Karazhanov
2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
M. Acosta ◽  
I. Riech ◽  
E. Martín-Tovar

Zinc oxide (ZnO) thin films were grown by nonreactive RF sputtering at room temperature under varying argon pressures (PAr). Their optical band gap was found to increase from 3.58 to 4.34 eV when the argon pressure increases from 2.67 to 10.66 Pa. After annealing at 200°C and 500°C, optical band gaps decrease considerably. The observed widening of the band gap with increasingPArcan be understood as being a consequence of the poorer crystallinity of films grown at higher pressures. Measurements of morphological and electrical properties of these films correlate well with this picture. Our main aim is to understand the effects ofPAron several physical properties of the films, and most importantly on its optical band gap.


2019 ◽  
Vol 6 (10) ◽  
pp. 190943 ◽  
Author(s):  
S. A. Saah ◽  
N. O. Boadi ◽  
D. Adu-Poku ◽  
C. Wilkins

Lead ethyl dithiocarbamates have been successfully used as single-source precursors for the deposition of PbS using spin coating followed by annealing at moderate temperatures. The thin films were characterized using a powder X-ray diffractometer and were found to be face-centred cubic with the (200) plane being the most preferred orientation. Scanning electron microscopy images showed the formation of well-defined cubes. Optical band gaps of PbS thin films were estimated using Tauc plots as 0.72, 0.73 and 0.77 eV at annealing temperatures of 250, 300 and 400°C. These band gaps were all blue shifted from the bulk value of 0.41 eV. Energy-dispersive X-ray analysis was used to determine the composition of the thin films which showed an approximately 1 : 1 Pb to S ratio.


2019 ◽  
Vol 719 ◽  
pp. 78-90 ◽  
Author(s):  
Laya Dejam ◽  
Shahram Solaymani ◽  
Amine Achour ◽  
Sebastian Stach ◽  
Ştefan Ţălu ◽  
...  

MRS Advances ◽  
2019 ◽  
Vol 4 (11-12) ◽  
pp. 733-742 ◽  
Author(s):  
Selina Ama Saah ◽  
Nathaniel Owusu Boadi ◽  
Christopher Wilkins

AbstractLead sulphide thin films have been successfully deposited by spin coating lead hexadecyl and octadecyl xanthate onto glass substrates and annealed at moderate temperatures. The thin films were characterized using powder x-ray diffractometer (p-XRD) and were found to be face centred cubic (FCC) with the (200) being the most preferred orientation. The optical band gaps obtained were 0.93 and 1.00 eV respectively for PbS from complexes (1) and (2) annealed at 350 °C. They were all blue shifted from the bulk value of 0.41 eV.


2010 ◽  
Author(s):  
Yijiao Qiu ◽  
Wei Li ◽  
Maoyang Wu ◽  
Junwei Fu ◽  
Yadong Jiang

2010 ◽  
Vol 34-35 ◽  
pp. 1421-1424
Author(s):  
Fei Hu ◽  
Zhi Yu He ◽  
Xiao Hong Li ◽  
Yue Hui Hu

Cuprous oxide films are successfully electrodeposited through the reduction of cupric ions in alkaline and acid electrolytes. The effect of electrodeposition parameters on the optical band gaps of Cu2O films is investigated using UV-vis spectroscopy. It is found that the optical transmittances and the band gaps of the Cu2O thin films are strongly influenced by the electrodeposition bath, the temperature, the current density, and the pH value. The band gaps are varied from 1.80 eV to 2.43 eV with different electrodeposition parameters.


RSC Advances ◽  
2015 ◽  
Vol 5 (75) ◽  
pp. 61118-61126 ◽  
Author(s):  
Debjit Kar ◽  
Debajyoti Das

In order to facilitate widening in optical band gaps utilizing quantum size-effects, self-assembled Si-ncs embedded in an a-Si matrix were grown within a-Si:H/nc-Si:H superlattice thin films produced by alternating sub-layers of a-Si:H and nc-Si:H.


1996 ◽  
Vol 436 ◽  
Author(s):  
Shu-Han Lin ◽  
Dong Li ◽  
Bernard J. Feldman

AbstractWe have grown cathode-mounted amorphous hydrogenated boron carbide thin films by rf plasma decomposition of diborane and methane. The chemical composition, infrared absorption, optical absorption, microhardness and adhesion of these thin films were measured. As a function of increasing diborane concentration in the feedstock, we observe increasing boron and decreasing hydrogen concentrations, increasing infrared absorption at 1300 cm-1 due to boron icosahedra, increasing optical band gaps, dramatically increased microhardness, and increased adhesion to the underlying substrates of these thin films. These results provide evidence that the presence of boron icosahedra increases microhardness, adhesion, and optical band gaps.


Sign in / Sign up

Export Citation Format

Share Document