Structural, optical and electrical measurements on boron-doped CdO thin films
- 203 Downloads
Several boron-doped CdO with different boron composition thin films have been prepared on glass substrate by a vacuum evaporation technique. The effects of boron doping on the structural, electrical and optical properties of the host CdO films were systematically studied. The X-ray diffraction study shows that some of B3+ ions occupied locations in interstitial positions and/or Cd2+-ion vacancies of CdO lattice. The band gap of B-doped CdO suffers narrowing by 30–38% compare to undoped CdO. Such band gap narrowing (BGN) was studied in the framework of the available models. Furthermore, a phenomenological evaluation of the dependence of band gap on the carrier concentration in the film samples is discussed. The electrical behaviours show that all the prepared B-doped CdO films are degenerate semiconductors. However, the boron doping influences all the optoelectrical properties of CdO. Their dc-conductivity, carrier concentration and mobility increase compare to undoped CdO film. The largest mobility of 45–47 cm2/V s was measured for 6–8% boron-doped CdO film. From near infrared transparent-conducting oxide (NIR-TCO) point of view, boron is effective for CdO donor doping.
KeywordsBoron Boron Oxide Boron Doping Vacuum Evaporation Technique Cadmium Borate
The author is grateful to Dr. K. I. Jassem and Ms. Hanan Khalifa from Central Labs/College of Science/SEM laboratory.
- 6.Chopra KL, Ranjan S (1993) Thin film solar cells. Plenum Press, New YorkGoogle Scholar
- 7.Powder diffraction file, joint committee for powder diffraction studies (JCPDS) file No. 05-0640Google Scholar
- 28.Kaelble EF (ed) (1967) Handbook of X-rays for diffraction, emission, absorption, and microscopy. McGraw-Hill, New York, p 5Google Scholar
- 33.Tauc J, Abelesn F (eds) (1969) Optical properties of solids. North Holland Publ. Co, AmsterdamGoogle Scholar
- 36.Pankove JI (1975) Optical processes in semiconductors, P.36. Dover, New YorkGoogle Scholar
- 44.Asahi R, Wang A, Babcock JR, Edleman NL, Metza W, Lane MA, Dravid VP, Kannewurf CR, Freeman AJ, Marks TJ (2001) In: Proceeding of the international symposium on transparent oxide thin films for electronics and optics, Tokyo, 8–9 NovGoogle Scholar