Study of n-ZnO/p-Si (100) thin film heterojunctions by pulsed laser deposition without buffer layer

Chirakkara, Saraswathi and Krupanidhi, SB (2012) Study of n-ZnO/p-Si (100) thin film heterojunctions by pulsed laser deposition without buffer layer. In: THIN SOLID FILMS, 520 (18). pp. 5894-5899.

PDF thin_solid_films_520-18_5894-5899_2012.pdf - Published Version Restricted to Registered users only Download (781kB) | Request a copy

Abstract

ZnO/Si heterojunctions were fabricated by growing ZnO thin films on p-type Si (100) substrate by pulsed laser deposition without buffer layers. The crystallinity of the heterojunction was analyzed by high resolution X-ray diffraction and atomic force microscopy. The optical quality of the film was analyzed by room temperature (RT) photoluminescence measurements. The high intense band to band emission confirmed the high quality of the ZnO thin films on Si. The electrical properties of the junction were studied by temperature dependent current-voltage measurements and RT capacitance-voltage (C-V) analysis. The charge carrier concentration and the barrier height (BH) were calculated, to be 5.6x10(19) cm(-3) and 0.6 eV respectively from the C-V plot. The BH and ideality factor, calculated using the thermionic emission (TE) model, were found to be highly temperature dependent. We observed a much lower value in Richardson constant, 5.19x10(-7)A/cm(2) K-2 than the theoretical value (32 A/cm(2) K-2) for ZnO. This analysis revealed the existence of a Gaussian distribution (GD) with a standard deviation of sigma(2)=0.035 V. By implementing the GD to the TE, the values of BH and Richardson constant were obtained as 1.3 eV and 39.97 A/cm(2) K-2 respectively from the modified Richardson plot. The obtained Richardson constant value is close to the theoretical value for n-ZnO. These high quality heterojunctions can be used for solar cell applications. (C) 2012 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	THIN SOLID FILMS
Publisher:	ELSEVIER SCIENCE SA
Additional Information:	Copyright for this article belongs to Elsevier
Keywords:	Zinc oxide; Heterojunction; Pulse laser deposition; Buffer layer
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	01 Aug 2012 11:14
Last Modified:	01 Aug 2012 11:14
URI:	http://eprints.iisc.ac.in/id/eprint/44892

Actions (login required)

View Item