Measurements of the bandgap of wurtzite InAs$_{1-x}$P$_x$ nanowires using photocurrent spectroscopy

We report measurements of the bandgap of InAs$_{1-x}$P$_x$ nanowires with wurtzite crystal structure as a function of the composition. The bandgap was measured using photocurrent spectroscopy (performed at 5 K) on single InAs nanowires with a centrally placed InAs$_{1-x}$P$_x$ segment, contacted at the InAs ends. The nanowires were grown with chemical beam epitaxy (CBE). The measured bandgap was larger than the bandgap of zincblende InAs$_{1-x}$P$_x$ by about 120 meV over the measured composition range, $0.15