Effect of piezoelectric field on type II transition in InAlAs/InP (311) alloys with different substrate polarity

A ternary Indium-Aliminium-Arsenic (InAlAs) is grown, by metal organic chemical vapor deposition (MOCVD), on a substrate InP (311) with polarity A and B, doped with Fer (Fe) atomic. Their optical properties have been studied by photoluminescence spectroscopy (PL) in the whole temperature range from 10 to 300 K. At low temperature region, power dependent analysis of the PL intensity reveals a conventional power law with an exponent n close to one, in agreement with the type II nature of the emission. A red shift of the type II transition has been observed from the sample with polarity A to B. The temperature-dependent PL measurements exhibit abnormal behaviors such as an S-shape in PL-peak energy, and an inverted N-shape in the full width at half maximum (FWHM). These atypical behaviors are linked to the exciton localization phenomenon, which it is more pronounced in the structure with polarity A of substrate orientation. Room temperature-PL spectra covers the both emissions of the 1.3 and the 1.55 μm for (311) A and (311) B InP oriented substrates, respectively. Our results indicate that the In0.513Al0.487As/InP (311) A/B is expected to be advantageous for their application in optical telecommunication.