Layer dependence and gas molecule absorption property in MoS(2) Schottky diode with asymmetric metal contacts

Surface potential measurement on atomically thin MoS(2) flakes revealed the thickness dependence in Schottky barriers formed between high work function metal electrodes and MoS(2) thin flakes. Schottky diode devices using mono- and multi- layer MoS(2) channels were demonstrated by employing Ti and Pt contacts to form ohmic and Schottky junctions respectively. Characterization results indicated n-type behavior of the MoS(2) thin flakes and the devices showed clear rectifying performance. We also observed the layer dependence in device characteristics and asymmetrically enhanced responses to NH(3) and NO(2) gases based on the metal work function and the Schottky barrier height change.