scholarly journals Current Voltage Characteristics and Excess Noise at the Trap Filling Transition in Polyacenes

2018 ◽  
Vol 17 (02) ◽  
pp. 1850014
Author(s):  
Jeremy Pousset ◽  
Eleonora Alfinito ◽  
Anna Carbone ◽  
Cecilia Pennetta ◽  
Lino Reggiani

Experiments in organic semiconductors (polyacenes) evidence a strong super quadratic increase of the current–voltage (I–V) characteristic at voltages in the transition region between linear (Ohmic) and quadratic (trap-free space-charge-limited current) behaviors. Similarly, excess noise measurements at a given frequency and increasing voltages evidence a sharp peak of the relative spectral density of the current noise in concomitance with the strong superquadratic I–V characteristics. Here, we discuss the physical interpretation of these experiments in terms of an essential contribution from field-assisted trapping-detrapping processes of injected carriers. To this purpose, the fraction of filled traps determined by the I–V characteristics is used to evaluate the excess noise in the trap-filled transition (TFT) regime. We have found an excellent agreement between the predictions of our model and existing experimental results in tetracene and pentacene thin films of different length in the range [Formula: see text].

1994 ◽  
Vol 361 ◽  
Author(s):  
Chang Jung Kim ◽  
Dae Sung Yoon ◽  
Joon Sung Lee ◽  
Chaun Gi Choi ◽  
Won Jong Lee ◽  
...  

ABSTRACTThe (100), (111) and randomly oriented PZT thin films were fabricated on Pt/Ti/Coming 7059 glass using sol-gel method. The thin films having different orientation were fabricated by different drying conditions for pyrolysis. The preferred orientations of the PZT thin films were observed using XRD, rocking curves, and pole figures. The microstructures were investigated using SEM. The hysteresis loops and capacitance-voltage characteristics of the films were investigated using a standardized ferroelectric test system. The dielectric constant and current-voltage characteristics of the films were investigated using an impedance analyzer and pA meter, respectively. The films oriented in a particular direction showed superior electrical characteristics to the randomly oriented films.


2016 ◽  
Vol 845 ◽  
pp. 224-227 ◽  
Author(s):  
Danila Saranin ◽  
Marina Orlova ◽  
Sergey Didenko ◽  
Oleg Rabinovich ◽  
Andrey Kryukov

This article presents the results of research output voltage characteristics of solar cells on an organic basis with the use of P3HT: PCBM system. There were produced organic solar cells in a coating in air, current-voltage characteristics were measured. It was determined the characteristic influence of a substrate cleaning and annealing temperature of layers applied on fill factor and conversion efficiency.


2011 ◽  
Vol 13 ◽  
pp. 87-92 ◽  
Author(s):  
M.S.P Sarah ◽  
F.S. Zahid ◽  
M.Z. Musa ◽  
U.M. Noor ◽  
Z. Shaameri ◽  
...  

The photoconductivity of a nanocomposite MEH-PPV:TiO2 thin film is investigated. The nanocomposite MEH-PPV:TiO2 thin film was deposited on a glass substrate by spin coating technique. The composition of the TiO2 powder was varied from 5 wt% to 20 wt% (with 5 wt% interval). The concentration of the MEH-PPV is given by 1 mg/1 ml. The current voltage characteristics were measured in dark and under illumination. The photoconductivity showed increment in value as the composition of the TiO2 is raised in the polymer based solution. The absorption showed augmentation as the amount of TiO2 is increased. The escalation of the current voltage is then supported by the results of surface morphology.


2013 ◽  
Vol 537 ◽  
pp. 114-117
Author(s):  
X.A. Mei ◽  
Rui Fang Liu ◽  
C.Q. Huang ◽  
J. Liu

La-doped bismuth titanate (Bi4-xLaxTi3O12: BLT) and pure Bi4Ti3O12 (BIT) thin films with random orientation were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique. These samples had polycrystalline Bi-layered perovskite structure without preferred orientation, and consisted of well developed rod-like grains with random orientation. For the samples with x=0.25 and 1.0 the current-voltage characteristics exhibited negative differential resistance behaviors and their P-V hysteresis loops were characterized by large leakage current, whereas for the samples with x=0.5 and 0.75 the current-voltage characteristics showed simple ohmic behaviors and their P-V hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization ( Pr ) and coercive field (Ec) of the BLT ceramic with x=0.75 were above 20μC/cm2 and 85KV/cm , respectively.


2002 ◽  
Vol 744 ◽  
Author(s):  
Galina Khlyap ◽  
Victor Brytan

ABSTRACTElectric field – induced effects are studied in thin films of amorphous Si grown by magnetron sputtering performed in continuous and pulse modes. Current-voltage characteristics are measured under the room temperature in different spectral ranges. It is shown that the investigated dependencies are of exponential character in all range of applied bias. Good photosensitivity was revealed by the samples prepared in continuous mode in the near-IR and visible interval. The samples grown by the pulse magnetron technology were shown room-temperature photosensitivity in near-IR range after 2000C hydrogenation.


2011 ◽  
Vol 337 ◽  
pp. 426-429
Author(s):  
S.B. Chen ◽  
Zhi You Zhong

Organic semiconductor thin films of bis-(2-methyl-8-quinolinolato)-4-(phenyl-phenolato) -aluminium-(III) (BAlq), N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)benzidine (NPB), and tris-(8- hydroxyquinoline) aluminum (Alq) were prepared by the vacuum sublimation technique. The optical properties in the UV-visible region of the thin films were investigated by optical transmittance and absorbance spectra. The optical energy gaps were obtained from direct allowed transitions at room temperature by Tauc’s law. The Urbach energy and the slope of Urbach edge were estimated by the Urbach-edges method, respectively. Furthermore, the current-voltage characteristics of organic thin films were analyzed, and the different slopes in the lower and higher voltage regions were observed. From the experimental studies, the effective carrier mobility, free carrier density, and electrical conductivity were also evaluated respectively.


2008 ◽  
Vol 104 (7) ◽  
pp. 073717 ◽  
Author(s):  
Soumen Samanta ◽  
Ajay Singh ◽  
A. K. Debnath ◽  
D. K. Aswal ◽  
S. K. Gupta ◽  
...  

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