The Defocusing And Current Anomalyof 2- Amino- 4- Phenyl Phenol

Under the irradiation of light, the change phenomenon of the refractive index of a material is photorefractive effect which is generally used in the optical information processing fields, such as: light amplification、oscillation、optical memories、the light image storage and recovery 、 spatial modulator 、 all-optical time integrator 、 image subtraction additive and inversion 、 image correlation and convolution etc. People observed the light scattering phenomenon in a lot of photorefractive crystals. As a kind of photorefractive effect, the defocusing phenomena in organic material is less observed in print. Through the experiment of organic small molecule materials, we have obviously observed the defocusing phenomena.This article focuses the defocusing phenomenon and current anomaly of these materials. The experiment part is mainly divided into the following three parts:The organic small molecule materials we chose to use are Hydroquinone 、4,4’-Biphenol、4-phenylphenol、2-amino-4-phenylphenol、4’-hydroxy-4-biphenylcarbonitrile、and 2-(4-hydro xypheny)-5-pyrimidinol. We configure the solution of different quality percentage and choose N, N – Dimethylformamide as the chemical solvent. Through the analysis of the experimental phenomena,we get the following conclusions: We obviously observed the defocusing phenomenon in the samples of 2-amino-4-phenylphenol、4’-hydroxy-4-biphenyl carbonitrile 、 2-4 hydroxypheny-5- pyrimidinol; We didn’t observe the defocusing phenomenon in the samples of Hydroquinone、4,4’-Biphenol、4-phenylphenol. The basic chemical structures of these samples are hydroquinone. When external groups are symmetrical state,we didn’t observe the defocusing phenomenon; When external groups are asymmetric state,we observed the defocusing phenomenon. The defocusing phenomenon of organic material is directly related to external groups of chemical structures. The effect of laser changes organic material molecular polarity, which produces the space charge field, and makes a laser beam to produce the defocusing phenomenon. The strength of the space charge field change along with the change of laser intensity. Polarization of the laser beam has no effect on the defocusing phenomenon. The z-scanning experiment of nanoseconds and picoseconds pulse laser beam proves that the defocusing phenomena of materials are not caused by the thermal effect. Moreover through the contrast experiment the defocusing phenomenon has nothing to do with the solvent.We studied the interface contact problems of several different metals and the organic small molecular material 2- amino- 4- phenylphenol, which get the following results: When the sandwich structure of the metal / 2- amino- 4- phenylphenol/the metal gave external voltage and the interface of the metal / 2- amino- 4- phenylphenol is ohmic contact, the curve of I/V shows symmetry; When interface of the metal / 2- amino- 4- phenylphenol is schottky contact, the curve of I/V shows asymmetric; The interface contact of Au / 2- amino-4 – phenylphenol/Au is not observed the current when the voltage is about 70 v. We speculatethat the conductive form of metal / 2- amino- 4- phenylphenol/metal is connected with largeπ bond of small organic molecules.We made the four terminals field effect tube to study the effect of electric field to 2-amino- 4- phenylphenol. Under the action of external electric field, the currents of samples will be changed with time period of oscillation. Our preliminary think that the reducing of lateral charge is enough to offset the effect of applied electric field. The uneven distribution of electric charge in a solution will make the equilibrium state collapse and reconstruction which form a periodic impulse oscillation figure.