TY - JOUR
T1 - Effect of carrier localization on modulation mechanism in photoreflectance of InGaPN
AU - Lin, K. I.
AU - Wang, T. S.
AU - Hwang, J. S.
N1 - Funding Information:
This work was supported by the National Science Council of Taiwan under contract nos. NSC95-2112-M-006-026 and NSC96-2112-M-006-020-MY2.
PY - 2008/4
Y1 - 2008/4
N2 - Photoreflectance (PR) and photoluminescence (PL) spectra are measured for In0.54Ga0.46P and In0.54Ga0.46P0.995N0.005 epilayers at temperatures ranging from 25 to 293 K. A dominant peak in PL spectra of InGaPN transits from free excitons (or carriers) to localized excitons (or carriers) when temperature is below 150 K. This transition is not observed in the N-free sample and is attributed to carrier localization at low temperatures resulting from N-related localized states in InGaPN. A decrease in the PR signal with falling temperature is also observed and is more pronounced in InGaPN. This effect is attributed to a weakening of modulation efficiency induced by the carrier localization effect seen in the low-temperature PL spectra. To understand the features in the PR spectra, the Kramers-Kronig relations are proposed to investigate the integrated intensity of PR transition, which provides a complement to the PL results.
AB - Photoreflectance (PR) and photoluminescence (PL) spectra are measured for In0.54Ga0.46P and In0.54Ga0.46P0.995N0.005 epilayers at temperatures ranging from 25 to 293 K. A dominant peak in PL spectra of InGaPN transits from free excitons (or carriers) to localized excitons (or carriers) when temperature is below 150 K. This transition is not observed in the N-free sample and is attributed to carrier localization at low temperatures resulting from N-related localized states in InGaPN. A decrease in the PR signal with falling temperature is also observed and is more pronounced in InGaPN. This effect is attributed to a weakening of modulation efficiency induced by the carrier localization effect seen in the low-temperature PL spectra. To understand the features in the PR spectra, the Kramers-Kronig relations are proposed to investigate the integrated intensity of PR transition, which provides a complement to the PL results.
UR - http://www.scopus.com/inward/record.url?scp=41349094867&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=41349094867&partnerID=8YFLogxK
U2 - 10.1016/j.physe.2007.11.003
DO - 10.1016/j.physe.2007.11.003
M3 - Article
AN - SCOPUS:41349094867
VL - 40
SP - 2188
EP - 2191
JO - Physica E: Low-Dimensional Systems and Nanostructures
JF - Physica E: Low-Dimensional Systems and Nanostructures
SN - 1386-9477
IS - 6
ER -