Tuning Of Thickness In Preparing Nanocrystal Cdte Film And Study On Its Properties

In this thesis, a new surfactant, CTAB, was added in electrodepositonbath containing cadmium sulfate as cadmium source, tellurium dioxide astellurium source and sodium sulfate as supporting electrolyte. A pure cubicCdTe thin film with ultra-fine structure was prepared and its properties werestudied.Firstly, the effect of electrodeposition condition, including current density,the temperature of the bath, pH value and concentration of main salt, on phaseformation and composition was well studied. A pure cubic CdTe thin film withgrain size of20nm and thickness of1μm was prepared. After the addition ofCTAB, the grain size decreased to15nm when the thickness reduced to497nm.Then, the relationship of the deposition time, film thickness andcomposition analysis was studied. It is found that CTAB had an effect onslowing the HTeO2+reduction reaction which reduced the amount of Tedeposition at the initial stage. Thus, the Cd/Te ratio could be controlled to be1:1at a lower thickness.Finally, UV-Vis spectra results showed that the film has a band gap of1.47eV which is suitable as solar cell absorption layer. Hall test resultsrevealed that p-type films had a low-resistance. The results of the IV curveillustrates that the photoelectric conversion properties of the films is best whenthe Cd/Te=1:1.