Optical and electrical properties of pure and doped tin oxide nanoparticles

Optical and electrical properties of pure, Co- and Mn-doped tin oxide (SnO2) nanoparticles (NPs) were studied and reported. The materials were successfully prepared by simple co-precipitation method. The developed SnO2 NPs exhibit tetragonal structure with space group P42/mnm. Addition of dopants reduces the particle size from 23 nm (pure SnO2 NPs) to 18 and 16 nm (Mn- and Co-doped SnO2 NPs). The estimated band gap energy of pure, Co-, and Mn-doped SnO2 NPs were found to be 3.43, 2.70 and 2.84 eV, respectively. FTIR and EDX analyses also confirmed the incorporation of Mn and Co into the pure SnO2 NPs. Scanning electron micrograph revealed that the synthesized NPs were formed as large spherical shape by the aggregation of small individual nanoparticle. Photoluminescence spectrum of synthesized NPs shows the emission peaks in the visible region. Electrical properties of the proposed materials were studied from current (I) and voltage (V) characteristics. The results confirm the semiconducting behavior of the material and the I-V curves of all the samples reveal the nonlinear behavior of the synthesized materials.