Effect of Temperature Cycling on Conduction Mechanisms in CdTe Thin Films

Srivastav, V and Pal, R and Saini, N and Saxena, RS and Bhan, RK and Sareen, L and Singh, KP and Sharma, RK and Venkataraman, V (2013) Effect of Temperature Cycling on Conduction Mechanisms in CdTe Thin Films. In: JOURNAL OF ELECTRONIC MATERIALS, 42 (3). pp. 389-397.

PDF jol_ele_mat_42-3_389_2013.pdf - Published Version Restricted to Registered users only Download (774kB) | Request a copy

Abstract

CdTe thin films of 500 thickness prepared by thermal evaporation technique were analyzed for leakage current and conduction mechanisms. Metal-insulator-metal (MIM) capacitors were fabricated using these films as a dielectric. These films have many possible applications, such as passivation for infrared diodes that operate at low temperatures (80 K). Direct-current (DC) current-voltage (I-V) and capacitance-voltage (C-V) measurements were performed on these films. Furthermore, the films were subjected to thermal cycling from 300 K to 80 K and back to 300 K. Typical minimum leakage currents near zero bias at room temperature varied between 0.9 nA and 0.1 mu A, while low-temperature leakage currents were in the range of 9.5 pA to 0.5 nA, corresponding to resistivity values on the order of 10(8) a''broken vertical bar-cm and 10(10) a''broken vertical bar-cm, respectively. Well-known conduction mechanisms from the literature were utilized for fitting of measured I-V data. Our analysis indicates that the conduction mechanism in general is Ohmic for low fields < 5 x 10(4) V cm(-1), while the conduction mechanism for fields > 6 x 10(4) V cm(-1) is modified Poole-Frenkel (MPF) and Fowler-Nordheim (FN) tunneling at room temperature. At 80 K, Schottky-type conduction dominates. A significant observation is that the film did not show any appreciable degradation in leakage current characteristics due to the thermal cycling.

Item Type:	Journal Article
Publication:	JOURNAL OF ELECTRONIC MATERIALS
Publisher:	SPRINGER
Additional Information:	Copyright for this article belongs to SPRINGER, NEW YORK
Keywords:	CdTe thin film;MIM;conduction mechanism;modified Poole-Frenkel;Richardson Schottky
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	14 Mar 2013 09:46
Last Modified:	14 Mar 2013 09:46
URI:	http://eprints.iisc.ac.in/id/eprint/45987

Actions (login required)

View Item