Photoconductivity of P-type semiconducting nanostructured Copper (I) Iodide (Cul) thin films / Nur Amalina Muhammad

The work presented here shows the effect of annealing temperature on Cul thin films. The Cul materials in thin film structure have been synthesized using the sol-gel method. The method used for thin film deposition was spin coating technique on glass and silicon substrates. Glass substrate is used for the purpose of characterization for electrical and optical properties. While for silicon substrates is used for structural properties characterization. The electrical, optical properties and surface morphology was characterized by Field Emission Scanning Electron Microscopy (FESEM), atomic force microscopy (AFM), UV-Vis-NIR measurement and two point probe I-V measurement. For the structural properties, FESEM images reveal noticeable transformation in film morphology among the films fabricated at various annealing temperatures. The nanostructed Cul thin films can be seen through AFM measurement. Next for optical properties, the study is concentrated on its transmittance, absorption cofficient and optical band gap. The Cul thin films exhibited an optical transmittance of 47%-80% at various annealing temperature in the wavelength of 400-800nm. The purpose for I-V measurement is to study its resistivity and conductivity. The I-V measurement in dark indicates that the resistivity decreases until the sintering temperature is -100°C. However, the resistivity of Cul under illumination is increasing since Cul tends to be oxidized under continuous illumination.