Probing the Wurtzite Conduction Band Structure Using State Filling in Highly Doped InP Nanowires

Abstract

We have grown InP nanowires doped with hydrogen sulfide, which exhibit sulfur concentrations of up to 1.4%. The highest doped nanowires show a pure wurtzite crystal structure, in contrast to bulk InP which has the zinc blende structure. The nanowires display photoluminescence which is strongly blue shifted compared with the band gap, well into the visible range. We find evidence of a second conduction band minimum at the gamma point about 0.23 eV above the band edge, in excellent agreement with recent theoretical predictions. Electrical measurements show high conductivity and breakdown currents of 10(7) A/cm(2).

Growth of doped InAsyP1−y nanowires with InP shells

“…Hydrogen sulfide (H 2 S) has been used for n-type doping [5,22] and diethyl zinc (DEZn) has been used for p-type doping [17] of InP NWs. We therefore investigated the doping of InAsP NW using these precursors.…”

Single GaInP nanowire p-i-n junctions near the direct to indirect bandgap crossover point

“…28 Regarding the S-doped NWs, the spectrum shows qualitative similarity with highly S-doped InP NWs. 21 Electrical measurements (see below) indicate quite high doping levels. We speculate that the high electron concentration leads to state-filling, causing the In-rich regions to be filled with electrons up to a common Fermi level.…”

“…The S-doped segment was almost pure wurtzite, similar to S-doped InP NWs. 21 We investigated the effect of doping on the composition of the ternary Ga x In 1Àx P NWs using energy dispersive x-ray spectroscopy (EDS) line scans along the length of p-i-n doped NWs, shown in Fig. 1(a).…”

Measuring the Energy Landscape in Single Semiconductor Nanowires

“…Similar saturation of the ground states can be accomplished by doping the nanowire. For example, Wallentin et al conrmed using PL in heavily doped WZ InP nanowires that the conduction band is in fact split as predicted theoretically by Pryor [14,23].…”