Open AccessStudy on photoluminescence properties of 1.05 eV InGaAsP layers grown by molecular beam epitaxy
Author(s) -
Weishen Yang,
Lian Ji,
Pengcheng Dai,
Minghong Tan,
Yuanyuan Wu,
Jianguo Lu,
Baoji Li,
Jun Gu,
Shulong Lu,
Ma Zhongquan
Publication year - 2015
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.64.177802
Subject(s) - photoluminescence , molecular beam epitaxy , materials science , relaxation (psychology) , spontaneous emission , excitation , band gap , luminescence , photoluminescence excitation , optoelectronics , molecular physics , optics , epitaxy , chemistry , physics , nanotechnology , laser , psychology , social psychology , layer (electronics) , quantum mechanics
The photoluminescence properties of InGaAsP films with a bandgap energy of 1.05 eV for quadruple-junction solar cells grown by molecular beam epitaxy (MBE) are investigated. We make the excitation intensity and temperature dependence of continuous-wave photoluminescence (cw-PL) measurements. The PL peak position is 1.1 eV at 10 K, and almost independent of the excitation power, but the integrated intensity of the PL emission peaks is roughly proportional to the excitation power. The shift of peak position with temperature follows the band gap shrinking predicted by the well-known Varshni's empirical formula. These results indicate that the intrinsic transition dominates the light emission of the InGaAsP material. In addition, we also make the time-resolved photoluminescence (TRPL) measurements to determine the carrier luminescence relaxation time in InGaAsP. PL spectra suggest that the relaxation time is 10.4 ns at room temperature and increases with increasing excitation power, which demonstrates the high quality of the InGaAsP material. However, the relaxation time shows an S-shape variation with increasing temperature: it increases at temperatures lower than 50 K, and then decreases between 50–150 K, and increases again when temperature is over 150 K. According to the effect of temperature and the non-radiative recombination center concentration on the carrier relaxation time, the recombination mechanism of S-shape variation can be explained by the carrier relaxation dynamics.