[17a-PA02-1~11] 9.2 ナノ粒子・ナノワイヤ・ナノシート

▲ [17a-PA02-11] Polarization dependence of quantum dot excitonic emission from InAsxP1-x/InP nanowire heterostructure

〇(P)Suman Mukherjee¹、Junichi Motohisa¹ (1.RCIQE, Hokkaido University)

キーワード：Exciton and biexciton, Quantum dot nanowire, Polarization dependence of PL

Polarization dependence of PL from excitons bound in QD layer in vertically grown InAsxP1-x/InP nanowire heterostructure has been studied. Sharp exciton (837meV) and biexciton (842meV) emission have been observed along with the near-bandgap c-hh emission (967 meV) from InAsxP1-x/InP QW by low-temperature (~ 4K) PL measurement (Fig.1). PL from QD-exciton (X) and biexciton (XX) has been confirmed by analyzing the measured excitation power dependence of the respective peak intensities (inset of Fig.1). From the measured T-dependent near-bandedge PL, As composition (x) in the strained embedded InAsxP1-x layer has been evaluated to be 0.55. Large FSS of 150 μeV has been evaluated for the X-emission by modelling the measured polarization dependent X-PL peak shift (Fig.2). This large X-FSS in this circularly symmetric wurtzite structure is most probably attributed to asymmetry of exciton wavefunction due to large lattice strain in the InAsxP1-x/InP hetero-interface with large x.