Impedance analysis of surface modified Ga0.5In0.5P—aqueous electrolyte interface

✍ Scribed by Shyam S. Kocha; John A. Turner

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 679 KB
• Volume: 41
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(95)00450-5

✦ Synopsis

In this work electrochemical impedance spectroscopy was carried out on pre-and post-etched Ga,,,In,,,P (1.8-1.9eV) as well as quinolinol-modified surfaces, over seven decades of frequencies. The spectra were examined in the Bode as well as complex impedance planes and deconvoluted using nonlinear-least-squares fitting to obtain equivalent circuits that isolated the space charge from the surface states. Chemical wet-etching of Ga,,,In,,,P was found to remove surface states as evidenced in the removal of the low frequency time constant from the spectra. Treatment with I-quinolinol was found to shift the flat-band potential in the positive direction vs. she by about 300mV in near neutral electrolytes.