Chemiresistive response to 2,4,6 trinitrotoluene vapors of large area arrays of Ge nanowires^*

Random arrays of Ge nanowires deposited on sapphire substrates were fabricated as chemiresistive sensors for the detection of nitroaromatic explosive vapors. We discuss the critical role played by reciprocal nanowires junctions on the electrical conduction and sensing performances. A mechanism is proposed to explain the high efficiency of the annealed arrays of nanowiress in detecting 2,4,6 trinitrotoluene vapors at ppb concentration.