Reducing a Piezoelectric Field in InGaN Active Layers by Varying Pattern Sapphire Substrates

Author

Chia-Feng Lin ; Kuei-Ting Chen ; Wang-Po Tseng ; Bing-Cheng Shieh ; Chang-Hua Hsieh

Author_Institution

Dept. of Mater. Sci. & Eng., Nat. Chung Hsing Univ., Taichung, Taiwan

Volume

60

Issue

12

fYear

2013

fDate

Dec. 2013

Firstpage

4180

Lastpage

4184

Abstract

Internal quantum efficiency (IQE) and piezoelectric field (PZ) in InGaN light-emitting diodes (LEDs) were analyzed that were grown on a truncated pyramid (TP)- and a pyramid (P)-shaped pattern sapphire substrates. Lower flat-band voltage was measured at -8 V in the P-LED compared with the TP-LED (-12 V) that showed a low PZ was observed in the P-LED structure. The IQE value of the P-LED was measured as 86%, which is higher than that of the TP-LED (76%). High IQE, low PZ, and high light extraction efficiency were observed in the InGaN LED structure grown on the P-shaped pattern sapphire substrate.

Keywords

light emitting diodes; piezoelectric materials; IQE; InGaN; LED structure; internal quantum efficiency; light emitting diodes; piezoelectric field; truncated pyramid; varying pattern sapphire substrates; voltage -12 V; voltage -8 V; Gallium nitride; Laser excitation; Light emitting diodes; Power lasers; Substrates; Voltage measurement; Wavelength measurement; InGaN; pattern sapphire; piezoelectric field (PZ);

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2013.2284918

Filename

6634237