Photo-Electric Response of Polyaniline/ZnO Nanocomposites Based on Inorganic/Organic Heterojunctions

Abstract

Abstract The samples were analyzed and characterized by scanning electronic microscope (SEM) and X-ray diffraction (XRD).The XRD results showed that the diffraction peaks of PANI/ZnO nanocomposites agreed with the pure ZnO. The as-prepared nanocomposites with different amounts of PANI dopants exhibited different sensing properties. When the weight ratio of PANI is 5%, the photoelectric response of nanocomposites to UV light reaches maximum (1938). Compared with ZnO, the response shows 60 times improvement. Additionally, the probable photoelectric response mechanism was also proposed. Firstly, the existence of p-n heterojunctions formed between p-type PANI and n-type ZnO interfaces was confirmed by the IV characteristics. It is believed that the p-n heterojunctions can promote the charge separation and further increase the amount of absorbed negative oxygen ions. Secondly, the highly dispersed stated of PANI could suppress the formation of interfacial recombination centers and accelerate p-type hole transporting. The photocurrent of composites is improved significantly. And we hope this work can help for designing more photoelectric materials with the higher response.