Ultrasonic Spray Pyrolysis And Physical Properties Of Sulfide Nanofilms

The ultrasonic spray pyrolysis technique has been one of the major techniques to deposit a wide variety of materials in film form. The prime require for obtaining good quality thin film is optimization of preparations conditions. However, in recent years an emphasis has been given to a variety of atomization techniques. Metal sulfide semiconductor nanofilm is intensively studied for its special properties. The ultrasonic spray pyrolysis technique for metal sulfide semiconductor nonafilm is improved, and the structure and characters of the film is studied.Part1: the ultrasonic spray pyrolysis technique (SP) is discussed especially on its advantages and disadvantages. In order to improve the SP, we improve the SP and name the new technology asynchronous ultrasonic spray pyrolysis (APUSP).Part2: nanophase polystslline thin films were deposited by asynchronous pulse ultrasonic spray pyrolysis method on glass substrates at relatively low temperature without any complexing agent. The films were characterized by X-ray diffraction, scanning electron microscopy, Dielectric test fixture and Raman spectrum. The technical conditions leading to optimal performance were identified. It can be concluded that and an appropriate ratio of pulse time to interval time between pulses is found to be necessary for obtaining homogeneous and uniform nonstructural film and the double dielectric model can give a reasonable explanation on dielectric property with nanostructures.Part3: nanorod array films were synthesized by an improved spray pyrolysis method, asynchronous ultrasonic spray paralysis, from BiCl₃, thiourea and iodine on amorphous substrates at relative low temperature. The surface morphology of the films, the phase and crystallinity of as-prepared films were characterized by scanning electron microscopy (SEM) and X-ray diffract meter (XRD).The mechanics was preliminarily studied that rod-like crystals grow along the direction vertical to the substrates. The dispersions of dielectric constant and dielectric loss with the variation of frequency were studied by LCR, respectively. The results show that the samples deposited by optimized techniques are highly preferred orientation polycrystalline film (JCPDS File 43-652: Bismuth Iodide Sulfide, Orthorhombic), and crystalline is rod-like and is expected that compound with nanorod structure can be obtained by the further study of APUSP. Dielectric properties measurement results show that there is a distinct difference between the films deposited by APUSP and those by Traditional Ultrasonic Spray Pyrolysis (TUSP). The nanorod films by APUSP have a high dielectric constant,low dielectric loss and a high visible absorption comparing with TUSP.