Measurement of Internal Electric Field in GaN-Based Light-Emitting Diodes

Author

Park, Su-Ik ; Lee, Jong-Ik ; Jang, Dong-Hyun ; Kim, Hyun-Sung ; Shin, Dong-Soo ; Ryu, Han-Youl ; Shim, Jong-In

Author_Institution

Dept. of Electron. & Commun. Eng., Hanyang Univ., Ansan, South Korea

Volume

48

Issue

4

fYear

2012

fDate

4/1/2012 12:00:00 AM

Firstpage

500

Lastpage

506

Abstract

The internal electric field due to the piezoelectric effect in an InGaN/GaN multiple quantum-well structure is measured via photoluminescence (PL), electroreflectance (ER), and photocurrent (PC) spectroscopies, and the measurement results are compared with each other and with theoretically calculated values. The flat-band voltage is estimated by measuring the applied bias voltage that induces the maximum in PL peak energy by the quantum-confined Stark effect, 180° phase shift in the ER spectrum, and the smallest band tail state in the PC spectrum. The internal electric fields estimated by the PL, PC, and ER spectra are -1.81, -2.12±0.14, and -2.04 MV/cm, respectively. The measured piezoelectric fields are in good agreement with theoretically calculated values. Possible factors affecting piezoelectric field measurements are discussed from various perspectives.

Keywords

III-V semiconductors; electric field measurement; gallium compounds; light emitting diodes; piezoelectricity; wide band gap semiconductors; InGaN-GaN; electroreflectance; internal electric field measurement; light emitting diodes; multiple quantum well structure; photocurrent spectroscopies; photoluminescence; piezoelectric effect; Current measurement; Electric fields; Gallium nitride; Modulation; Quantum well devices; Voltage measurement; Electroreflectance; GaN; light-emitting diodes; modulation spectroscopy; photocurrent; piezoelectric field; polarization; strain;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/JQE.2012.2186610

Filename

6145600