Synthesis of high quality p-type Zn3P2 nanowires and their application in MISFETs

Abstract

Single-crystalline Zn 3 P 2 nanowires (NWs) have been synthesized on silicon (Si) substrates via a vapor phase transport method. Zn (99.99%) powder and InP (99.99%) fragments were used as the sources, and 10 nm thick thermal evaporated gold (Au) film was used as the catalyst. The as-prepared Zn 3 P 2 NWs have diameters of 100-200 nm and lengths of more than 10 mm. Single NW metalinsulator-semiconductor field-effect transistors (MISFETs) based on Zn 3 P 2 NWs were fabricated. Electrical transport measurements show that the as-grown Zn 3 P 2 NWs are of p-type. The hole concentrations and mobilities of the p-type Zn 3 P 2 NWs are about 5.6 Â 10 16 cm À3 and 42.5 cm 2 V À1 s À1 , respectively. The on-off ratio of the MISFET is about 4 Â 10 4 , and its threshold voltage and transconductance are 2.5 V and 35 nS, respectively. These parameters indicate that the p-type Zn 3 P 2 NWs are of high quality, and may have potential applications in nanoscale electronic and optoelectronic devices.

A novel synthetic route to transition metal phosphide nanoparticles

“…10 Although the Co 2 P phase (2θ=40.8, 43.4, 44.2 and 52.1 o , indexing respectively to (121), (211), (130) and (002) planes) appeared to be good quality at above 600 o C, the Co 3 (PO 4 ) 2 species (see Fig. 3 in detail) can not be reduced until the temperature reached 700 o C. The XRD result indicated that 15 phase-pure Co 2 P can be obtained at temperatures of above 700 o C. For the sake of comparison, Table 1 summarizes the phase structures of the samples obtained in this study. It was clear from Table 1 that pure MoP and Co 2 P can be obtained by 25 reduction of their corresponding precursors in DME at above 700 o C. In the case of Ni phosphide, reduction temperature was the key factor in the synthesis.…”

“…27 It was suggested that the surface concentration of Ni 12 P 5 species on N-800 sample was too low to be detected by XPS. The result appeared to be 15 reasonable because only a small amount of Ni 12 P 5 phase was identified by XRD pattern of N-800 and this phase was also oxidized more readily than Ni 2 P phase in the passivation process. 39 Finally, the morphology and element composition of the as- 25 prepared metal phosphides (M-800, N-800 and C-800) were investigated.…”

“…11 10 preparation, a new method, rapid heating reduction in dimethyl ether (RHR-DME), was utilized to convert the oxide precursors into phosphides. The reduction of these oxide precursors (further designated as M for MoP, N for Ni 2 P and C for Co 2 P) was carried out in a quartz reactor placed in a 15 furnace controlled by a temperature programmer. The temperature was increased linearly at 10 o C min -1 and kept at a given value for 1 h. A pure DME gas was used and the flow rate was set at 100 ml min -1 .…”

“…Therefore, in this temperature region, the precursors 10 might undergo reduction by DME together with its thermal decomposition products (CH 4 and H 2 ). (iii) high temperature region: T≥720 o C. In the case of the profiles of N and C precursors, the species concentration would tend to reach a new steady state, showing the final 15 reduction step. However, as for the profile of M, the concentration of H 2 and CO x increased continuously but CH 4 concentration decreased slowly with temperature, providing an evidence that CH 4 produced from DME was involved in the final reduction step.…”

“…2,9 Since the discovery of size- 25 dependent catalytic properties for materials with size scales of less than 100 nm, extensive effort has been focused on synthetic routes for the preparation of nanoscale metal phosphides. In the lastest review published in 2013, a wide range of methods have been summarized for the synthesis of 30 nano-sized metal phosphides, 10 such as direct reduction of phosphate in H 2 , 11 a solid-state reaction route using red or white phosphorus, 12,13 decomposition of single-source precursors in solution or by chemical vapor deposition, 14,15 decomposition of high-boiling point tri-n-octylphosphine 35 (TOP) 16,17 or P(SiMe 3 ) 3 , 18,19 and solvothermal or hydrothermal synthesis. 20 There are various kinds of phosphides with high quality obtained by these methods mentioned above.…”