Synthesis of surfactant-assisted nanostructured Bi-doped Zinc oxide for photo-sensing application

Nanostructures are expected to have more potential applications for the functional electronic devices and to obtain the novel opto-electronic properties. Therefore, many researches have been attempted to synthesize nanostructured ZnO in a controllable properties such as nanocrystal size, optical and electrical properties in order to gain the variety of microelectronic applications. This work studies the effect of surfactant on the surface quality, structure and photo-sensing properties of Bi-doped ZnO synthesized by sol-gel spin coating. The experimental was carried out a mixture solution of bismuth nitrate pentahydrate and zinc acetate dehydrate as precursors for Bi-doped ZnO film. Meanwhile, Cetyltrimethylammonium bromide (CTAB) as a surfactant has been used for quality enhancement of the obtained Bi-ZnO films. The variation in surface morphologies and electrical conductivity was found with the different CTAB quantity. By using 2-probe technique with screen-printing to fabricate the metal contacts, the photocurrent of Bi-ZnO film was enhanced by 10³ times under the low illumination intensity 17.7mW/cm² comparing with the current under the dark condition. The result is suggested that CTAB is an important role to assist the quality of Bi-doped ZnO film surface and to improve the photocurrent. Therefore, the prepared Bi-doped ZnO film with CTAB assisted is useful for the effective guidance in the further investigation of photo-sensing devices.