Direct band gap III–V
semiconductors, emitting efficiently
in the amber–green region of the visible spectrum, are still
missing, causing loss in efficiency in light emitting diodes operating
in this region, a phenomenon known as the “green gap”.
Novel geometries and crystal symmetries however show strong promise
in overcoming this limit. Here we develop a novel material system,
consisting of wurtzite AlxIn1–xP nanowires, which is predicted to have a direct
band gap in the green region. The nanowires are grown with selective
area metalorganic vapor phase epitaxy and show wurtzite crystal purity
from transmission electron microscopy. We show strong light emission
at room temperature between the near-infrared 875 nm (1.42 eV) and
the “pure green” 555 nm (2.23 eV). We investigate the
band structure of wurtzite AlxIn1–xP using time-resolved and temperature-dependent photoluminescence
measurements and compare the experimental results with density functional
theory simulations, obtaining excellent agreement. Our work paves
the way for high-efficiency green light emitting diodes based on wurtzite
III-phosphide nanowires.