"

Cookies ussage consent

Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our site without changing the browser settings you grant us permission to store that information on your device.

I agree, do not show this message again.

The origin of anomalous peak and negative capacitance in the forward bias C-V characteristics of Au/n-GaAs contacts at low temperatures (T≤300 K)

ILBILGE DOKME1, SECKIN ALTINDAL YERISKIN2, MERT YILDIRIM3,* , PERIHAN DURMUS4

Affiliation

  1. Science Education Department, School of Gazi Education, Gazi University, 06500 Ankara, Turkey
  2. Chemical Engineering Department, Faculty of Engineering, Gazi University, 06500 Ankara, Turkey
  3. Mechatronics Engineering Department, Faculty of Engineering, Duzce University, 81620 Duzce, Turkey
  4. Department of Physics, Faculty of Arts and Sciences, Gazi University, 06500 Ankara, Turkey

Abstract

Au/n-GaAs contacts were fabricated using n-GaAs wafer with high doping concentration and their electrical characteristics were investigated via admittance measurements at low temperatures (T300 K) at 1MHz. The main electronic parameters such as barrier height, depletion region width, doping concentration, series resistance and Fermi energy were obtained from experimental data. All these parameters showed dependence on temperature since different conduction mechanisms may play role at a certain voltage and temperature range. The forward bias capacitance-voltage curve exhibited an anomalous peak and then capacitance took negative values for each temperature. Such negative capacitance behaviour can be explained by the loss of interface charges located at junction, the existence of surface states, series resistance and a native interlayer. The decrease in series resistance and increase in surface states with increasing temperature were attributed to the decrease in band gap of GaAs and restructuring and reordering of surface charges..

Keywords

Au/GaAs contacts, Temperature dependence, Negative capacitance, Anomalous peak, Surface states, Series resistance.

Submitted at: March 19, 2019
Accepted at: April 9, 2020

Citation

ILBILGE DOKME, SECKIN ALTINDAL YERISKIN, MERT YILDIRIM, PERIHAN DURMUS, The origin of anomalous peak and negative capacitance in the forward bias C-V characteristics of Au/n-GaAs contacts at low temperatures (T≤300 K), Journal of Optoelectronics and Advanced Materials Vol. 22, Iss. 3-4, pp. 149-155 (2020)