The frequency dependence of forward capacitance-voltage characteristics of Schottky barrier diodes were investigated by considering the series resistance effect. It is seen that in presence of a series resistance, the capacitance-voltage plot exhibits a peak. The peak value of the capacitance is found to vary with series resistance, interface state density and the frequency of the a.c. signal. The effect of series resistance on the capacitance is found appreciable at higher frequencies when capacitance decreases rapidly with frequency. On the other hand, the conductance of the diode increases with frequency in the high frequency limit. Such a variation in conductance limits the use of well known conductance technique to determine interface state density. © 1993.

PROJNAN CHATTOPADHYAY

Electronic Science

B RAYCHAUDHURI

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

&nbsp;

The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

&nbsp;

It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Frequency dependence of forward capacitance-voltage characteristics of Schottky barrier diodes

Solid State Electronics

The effects of Schottky-ohmic separation length on the capacitance and ac resistance of Al-p-Si Schottky barrier diodes in planar configuration have been studied. It has been found that the capacitance of such devices depends upon the Schottky-ohmic separation length. While the variation of the capacitance with Schottky-ohmic separation length shows a decreasing trend at all measurement frequencies, the ac resistance of the device remains almost constant at high frequency though some nonlinearity with respect to Schottky-ohmic separation length has been noticed at lower frequencies. The dependence of the capacitance of the device with Schottky-ohmic separation length is analyzed and empirical relations are obtained by fitting the experimental data by linear trend lines. © 2017 EDP Sciences.

EPJ Applied Physics

Effect of Schottky-ohmic separation length on the ac properties of planar Schottky barrier diode

The sub-band gap optical absorption in silver sulphide thin films prepared by chemical conversion technique has been studied in the light of Urbach absorption law at different annealing temperatures. The study reveals the Urbach absorption parameters and band gap of the material are sensitive to annealing temperature. Interestingly, these parameters undergo a sudden change as the annealing temperature exceeds a certain critical value. The observed changes in the values of absorption parameters have been attributed to the structural phase transition and the modification of grain boundary interfaces and/or changes in the crystallographic orientation due to annealing. © 2014 AIP Publishing LLC.

Fulltext

Journal of Applied Physics

Effects of annealing and structural phase transformation on the Urbach absorption in thin silver sulphide films

The sub-band gap optical absorption in chemical bath deposited cadmium sulphide thin films annealed at different temperatures has been critically analyzed with special reference to Urbach relation. It has been found that the absorption co-efficient of the material in the sub-band gap region is nearly constant up to a certain critical value of the photon energy. However, as the photon energy exceeds the critical value, the absorption coefficient increases exponentially indicating the dominance of Urbach rule. The absorption coefficients in the constant absorption region and the Urbach region have been found to be sensitive to annealing temperature. A critical examination of the temperature dependence of the absorption coefficient indicates two different kinds of optical transitions to be operative in the sub-band gap region. After a careful analyses of SEM images, energy dispersive x-ray spectra, and the dc current-voltage characteristics, we conclude that the absorption spectra in the sub-band gap domain is possibly associated with optical transition processes involving deep levels and the grain boundary states of the material. © 2013 AIP Publishing LLC.

On the sub-band gap optical absorption in heat treated cadmium sulphide thin film deposited on glass by chemical bath deposition technique

The effect of aging on the electrical properties of a nickel contact on p-type silicon (Si) were analyzed. The aging characteristics were studied by measuring the electrical characteristics at different intervals of time. The current-voltage (I-V) characteristics showed a decrease in the current over time for the first few measurements, followed by an insignificant change for longer aging. The results show that the barrier height derived from I-V characteristics increased form an initial value to a final higher value after a prolonged period of aging.

Aging characteristics of nickel contact on p-type silicon

The admittance of a metal-insulator-semiconductor tunnel contact is evaluated considering the presence of donor-acceptor mixed interface states and chemical reaction in the interfacial oxide layer. Both the voltage and frequency behavior of the device has been studied. It has been found that, due to interface reaction, the current, conductance, and capacitance of the device drift considerably with time yielding an aging effect. Further, it is revealed that the dependence of the conductance and capacitance on the aging time stem rapidly from changing time constants of the interface states with aging time. The results are discussed with special reference to well known admittance spectroscopy used for the characterization of interface states. © 2001 American Institute of Physics.

Journal	Solid State Electronics
Publisher	-
ISSN	0038-1101
Open Access	No