Investigation of trapping levels in p-type Zn3P2 nanowires using transport and optical properties

Abstract

Here, we report the synthesis and structural characterization of high-quality Zn3P2 nanowires via chemical vapour deposition. Structural and morphological characterization studies revealed a reliable growth process of long, uniform, and single-crystalline nanowires. From temperature dependent transport and photoluminescence measurements, we have observed the contribution of different acceptor levels (15, 50, 70, 90, and 197 meV) to the conduction mechanisms. These levels were associated with zinc vacancies and phosphorous interstitial atoms which assigned a p-type character to this semiconductor. From time resolved photoluminescence experiments, a 91 ps lifetime decay was found. Such a fast lifetime decay is in agreement with the exciton transition along the bulk emission from high quality crystalline nanowires.

Multiple morphologies and functionality of nanowires made from earth-abundant zinc phosphide

“…13,14,[33][34][35] Previously, in addition to thin films and bulk crystals, Zn 3 P 2 has been obtained in the form of randomly oriented nanowires, nanoribbons, and nanotrumpets. [36][37][38][39][40][41][42][43] In most of these studies, nanowires were produced through chemical vapour deposition (CVD) or by a thermochemical method relying on a quartz capsule containing the precursors being heated in a furnace. 36,37,[39][40][41]43 Both of these techniques result in a nanowire powder consisting of randomly aligned nanowires not attached to a substrate.…”

“…[36][37][38][39][40][41][42][43] In most of these studies, nanowires were produced through chemical vapour deposition (CVD) or by a thermochemical method relying on a quartz capsule containing the precursors being heated in a furnace. 36,37,[39][40][41]43 Both of these techniques result in a nanowire powder consisting of randomly aligned nanowires not attached to a substrate. To achieve the 1D nanowire morphology, researchers have mainly relied on the vapour-liquid-solid (VLS) growth mechanism, where a nanoscale liquid catalyst is used to guide 1D growth through enhanced precursor absorption and selective, directional precipitation upon supersaturation.…”

“…44 The catalysts previously reported for zinc phosphide nanowire growth are gold, indium and tin. 36,[39][40][41]45 Whilst gold catalysed nanowires tend to be straight, those grown with indium and tin exhibited a zigzag morphology. 36,39,40,45 Similar superlattice structures have also been reported for other compound semiconductors.…”

“…36,[39][40][41]45 Whilst gold catalysed nanowires tend to be straight, those grown with indium and tin exhibited a zigzag morphology. 36,39,40,45 Similar superlattice structures have also been reported for other compound semiconductors. According to Algra et al, twinning minimises the deformation of the droplet on the top facet when the cross-section reaches a truncated triangular geometry, and turns it back to a hexagon.…”

Heterotwin Zn3P2superlattice nanowires: the role of indium insertion in the superlattice formation mechanism and their optical properties

“…35,36 The synthesis of Zn 3 P 2 nanowires can follow the VLS and the vapour-solid mechanisms, with In, Sn, and Au as catalysts. 9,24,[32][33][34]37,38 Zn 3 P 2 nanowires adopt various morphologies depending on the fabrication method and/or growth conditions, including a zigzag superlattice. 9,24,[32][33][34] In contrast with III-V compound semiconductors, Zn 3 P 2 exhibits a centrosymmetric tetragonal structure, and thus also non-polar facets and main crystal symmetry directions.…”