Nanocomposites and nanomaterials

Composite polymer films with semiconductor nanocrystals for organic optoelectronics
Pylypova O.1, Evtukh A.1,2, Shmahlii S.2, Korbutyak D.2, Tokarev V.3
1Taras Shevchenko National University of Kyiv, Institute of High Technologies, Kyiv, Ukraine. E-mail: steblolia@gmail.com
2 V. Lashkaryov Institute of Semiconductor Physics NAS of Ukraine 41 pr. Nauki, 03028, Kyiv, Ukraine.
3 Lviv Polytechnic National University, 79013, Lviv, Ukraine.

Doped nanostructured II–VI semiconductors have been used extensively due to their industrial implementation in nanoelectronicn and optoelectronic devices [1]. Cadmium sulphide (CdS) is one of the cheapest semiconducting material from same group, the deposition and characterization of CdS semiconducting thin films has been received a considerable amount of interest due to their potential application in the area of electronic and opto-electronic devices fabrications such as solar cells, photoconductor, laser material, optical wave-guide, and non-linear integrated and optical device [2]. The purpose of this paper is to investigate the conductivity of composite polymer films with CdS and CuS  under the influence of light and without it, in order to determine their prospects for organic optoelectronics. CdS and CuS nanocrystals were synthesized by the method of low temperature (T = 25 ° C) colloidal synthesis in a semi-continuous mixing reactor in the presence of thioglycolic acid as a stabilizer and, moreover, ethylene glycol as a stabilizer promoter, and deionized water were served as a dispersion medium. The formation of film structures was carried out by mixing 51.5% aqueous copolymer of vinyl acetate acrylate with colloidal solutions in a ratio of 3: 1 followed by application on a glass substrate and exposure at a temperature of 30 ° C for 5 hours in the absence of illumination. The current-voltage characteristics of composite films with different ratios of CdS and CuS nanocrystals without and under irradiation have been measured. The conductivity of composite polymer based films as under illumination and without does not depend on the ration of CdS and CuS nanocrystals. The mechanism of electron transport at measurement without illumination is direct tunneling. But under illumination the the Poole-Frenkel electron transport mechanism is realized. In this case the potential barrier is φb=0.46 eV for film with 40% CdS:60% CuS and φb = 0.5 eV for film with 0% CdS:100% CuS. 
  1. A. S. Khomane,// Archives of Applied Science Research.-2011.- 3.-P.273-279. 
  2. D. J. Desale, S. Shaikh, F. Siddiqui, A. Ghosh, R. Birajdar, A. Ghule, R. Sharma, // Pelagia Research Library: Advances in Applied Science Research.-2011.-2.-P.417-425