Cotton fiber as a semiconductor material

Full text: It was shown earlier using electron-microscopic measurements, that cotton fiber are nanostrctured material [1]. Further studies on this topic may allow to reveal new properties of such structure and construct novel, highly efficient electronic devices using this material. In this work we present recent results on the experimental study of some physical properties of cotton fiber. In our experiments we used mature cotton fibers. The patterns were prepared in the form of (5000-8000) parallel fiber bundles with total mass 3 -5 mg. The length of the pattern was 4 -8 mm. The result of experiment showed that cotton fiber is semiconductor and its electric conductivity grows exponentially as the temperature increases. In iodide doped cotton fiber the electric conductivity increases 10- 10000 times. It is found also that the valence zone band width of cotton fiber reaches Eg=3,2 eV. In addition, photoconductivity and infrared suppression of the cotton fiber is found at the room temperature. It is also revealed that iodide doping leads to appearing of deep levels in the valence band. Furthermore, it is found that the physical properties of the cotton fiber is highly sensitive to such external perturbations as light, temperature, pressure and doping of chemical elements. Using the result of studies we succeeded to construct photovoltaic elements, thermo- and photoresistors and heterophotodiods. (authors) References: [1]. Kh.U. Usmanov, G.V.Nikonovich. Electron microscopy of cellulose. Tashkent, Fan publishers, 1962.