Analytical determination of the density-of-gap-states distribution in amorphous semiconductors: Experimental results

1987 ◽  
Vol 35 (2) ◽  
pp. 614-618 ◽  
Author(s):  
V. Augelli ◽  
V. Berardi ◽  
R. Murri ◽  
L. Schiavulli ◽  
M. Leo ◽  
...  
1986 ◽  
Vol 33 (10) ◽  
pp. 7392-7394 ◽  
Author(s):  
V. Augelli ◽  
M. Leo ◽  
R. A. Leo ◽  
G. Soliani

1987 ◽  
Vol 95 ◽  
Author(s):  
R. B. Jones ◽  
G. Moddel

AbstractA method for determining the density of states [N(E)] in the upper half of the energy gap in hydrogenated amorphous silicon (a-Si:H) is proposed and experimental results are simulated. The method involves the growth and measurement of the planar conductivity in multilayer films in which each layer is separated by a thermally grown oxide. Band-bending occurs at each interface throughout the film thickness. The conductivity parallel to the layers in the films is a function of the band-bending, which in turn depends on N(E), in the energy range through which the Fermi level is shifted. Computer simulations of the oxide-induced band-bending have been used to generate curves of the conductivity as a function of layer-thickness for various N(E). By matching experimental results with the simulation curves, the N(E) may be deduced. The simulations have also been used to show the difference between the bulk conductivity activation energy and effective activation energy which is measured in films influenced by a surface oxide.


2020 ◽  
Vol 50 (5) ◽  
pp. 347-350
Author(s):  
G. M. Druzhinin ◽  
N. B. Loshkarev ◽  
E. D. Solntseva ◽  
I. M. Khammatov

2020 ◽  
Vol 835 ◽  
pp. 229-242
Author(s):  
Oboso P. Bernard ◽  
Nagih M. Shaalan ◽  
Mohab Hossam ◽  
Mohsen A. Hassan

Accurate determination of piezoelectric properties such as piezoelectric charge coefficients (d33) is an essential step in the design process of sensors and actuators using piezoelectric effect. In this study, a cost-effective and accurate method based on dynamic loading technique was proposed to determine the piezoelectric charge coefficient d33. Finite element analysis (FEA) model was developed in order to estimate d33 and validate the obtained values with experimental results. The experiment was conducted on a piezoelectric disc with a known d33 value. The effect of measuring boundary conditions, substrate material properties and specimen geometry on measured d33 value were conducted. The experimental results reveal that the determined d33 coefficient by this technique is accurate as it falls within the manufactures tolerance specifications of PZT-5A piezoelectric film d33. Further, obtained simulation results on fibre reinforced and particle reinforced piezoelectric composite were found to be similar to those that have been obtained using more advanced techniques. FE-results showed that the measured d33 coefficients depend on measuring boundary condition, piezoelectric film thickness, and substrate material properties. This method was proved to be suitable for determination of d33 coefficient effectively for piezoelectric samples of any arbitrary geometry without compromising on the accuracy of measured d33.


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