Optoelectric Properties of Thermally Evaporated ClAlClPc Thin Films

Author(s) Raji Koshy , C.S. Menon
Affiliations School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala, 686560, India
Е-mail rajirose23@yahoo.com
Issue Volume 3, Year 2011, Number 1, Part 3
Dates Received 04 February 2011, in final form 18 June 2011, published online 23 June 2011
Citation Raji Koshy, C.S. Menon, J. Nano- Electron. Phys. 3 No1, 521 (2011)
PACS Number(s) 78.20.Jq, 78.40. – q
Key words Chloro aluminium chloro phthalocyanine, Thin films (51) , Phthalocyanine (4) , Optical properties (17) , Electrical properties (14) .
Vacuum sublimed thin films of Chloro Aluminium Chloro phthalocyanine were prepared at room temperature onto glass substrates at a base pressure of 10 -5 Torr. Annealing was done in air and the effect of annealing temperature on the optical and electrical properties were studied. Optical absorption spectra of films annealed at temperatures, 373 K, 423 K, 473 K and as-deposited were taken over a wavelength range of 200 to 900 nm and the optical energy band gap Eg and the onset and excitonic energy gap were calculated. It is found that Eg slightly increases with increase in air annealing temperature and excitonic energy gap has practically unchanged. Arrhenius plot yields thermal activation energy in the intrinsic region and impurity scattering region. The variation in the electrical properties with air annealing temperature were also studied and activation energy was determined. Thermal activation energy is calculated from the Arrhenius plot in the intrinsic and extrinsic regions, it is found that it decreases with increase in the air annealing temperatures.