Transient photo-induced absorption in InGaN thin films

Author

Nomura, M.-S. ; Arita, M. ; Ashihara, S. ; Kako, S. ; Arakawa, Y. ; Shimura, T. ; Kuroda, K.

Author_Institution

Inst. of Ind. Sci., Tokyo Univ., Japan

Volume

1

fYear

2003

fDate

27-28 Oct. 2003

Firstpage

256

Abstract

Structure dependent absorption spectrum changes In_0.10Ga_0.90 thin films of different thickness (5.5, 17, 34, and 66 nm) are investigated by nondegenerate femtosecond pump and probe spectroscopy at room temperature. These spectrum changes are caused by excitonic absorption quenching and screening of internal piezoelectric fields by photo-induced carriers. Both fast (500 ps) and slow (100 μs) temporal behaviors are observed in differential absorption spectra. Localized carriers in indium-rich regions and/or carriers captured in midgap traps are considered to keep screening the internal filed and to maintain absorption spectrum changes much longer than the photoluminescence lifetimes.

Keywords

II-VI semiconductors; high-speed optical techniques; indium compounds; photoluminescence; radiation quenching; radiative lifetimes; semiconductor thin films; time resolved spectra; 100 mus; 20 degC; 500 ps; In_0.10Ga_0.90; InGaN thin films; absorption spectrum; differential absorption spectra; excitonic absorption quenching; excitonic absorption screening; internal piezoelectric fields; localized carriers; nondegenerate femtosecond spectroscopy; photoinduced carriers; photoluminescence lifetimes; pump and probe spectroscopy; room temperature; transient photoinduced absorption; Absorption; Electron traps; Photoluminescence; Probes; Pulse amplifiers; Radiative recombination; Spectroscopy; Spontaneous emission; Transistors; Ultrafast optics;

fLanguage

English

Publisher

ieee

Conference_Titel

Lasers and Electro-Optics Society, 2003. LEOS 2003. The 16th Annual Meeting of the IEEE

ISSN

1092-8081

Print_ISBN

0-7803-7888-1

Type

conf

DOI

10.1109/LEOS.2003.1251734

Filename

1251734