Study On Optical And Electronic Measurement Methods For The Preparation Of Organic Thin Films

After decades of development, organic thin-film devices have been brought intoindustry from research institute. The devices based on organic thin films, such asorganic light-emitting diode (OLED) and photovoltaic devices (OPVD), have beenexpanding their market share rapidly. The performance of the organic devices whosefunctional core is organic thin films is impacted greatly by the structures of thin filmsand the features of organic-substrate interface as well as molecular properties. It issignificant to carry out measuring and monitoring during thin films growth as thisprocess determines qualities of films. This paper focused on the measurement scienceand technology applied in in-situ detection of films manufacture.The main works in this paper include the following aspects:1) The present research situation and specific applications of the organic films werereviewed. Differential Reflectance Spectroscopy was selected as an on-linedetection method after the study of several kinds of organic film growth patternand the comparison of different films’ surface characterization techniques andtheir advantages and disadvantages. A measuring optical system was designedand built, the vacuum chamber microscopy was realized, and the optical signalswere processed and analyzed after studying principle and technology of test.Depending on the analysis of noise sources in optical path system, the experimentsystem was improved: the errors were controlled within a permitted scale and thedrift of data declined to less than2*10-3while system had been measuring for200minutes.2) The best scheme for organic field effect transistor testing was selected aftercomparing several commonly used methods for the test of organic thin-filmdevices. An electrical measurement system with a high accuracy better than0.1nA was established, and the collected experimental data were processed.Combined with atomic force microscope, optical microscope and other testingmeans, the influence of different growth processes on the properties of organicthin-film devices was analyzed and compared.3) The electrical properties of several common organic thin-film materials werecompared, and the appropriate ones that can meet the experimental requirements were selected. A platform for the test of organic thin-film optical and electroniccharacteristics was completed. The preparation methods of organic thin-filmdevices were designed and implemented. Pentacene was chosen as theexperimental organic thin film materials, and the impacts of different growthconditions on the devices were analyzed by changing the growth process of thinfilms. The platform of testing organic thin films’ optical and electroniccharacteristics had been gradually established.