Study on molybdenum disulfide layer growth on gallium nitride surface for high efficiency UV-visible photodetector

在本研究中，我们提出开发二硫化钼（MoS2）和氮化镓（GaN）异质结用于短波长光电探测器应用。在这一前景中，我们研究了用化学气相沉积（CVD）方法在GaN表面上货车德瓦尔异质外延生长MoS2薄膜。以四硫代钼酸铵为前驱体，采用化学气相沉积（CVD）技术在Ga封端的GaN衬底上合成了三角形的MoS2晶体。通过CVD工艺在GaN衬底表面生长出具有相同取向的三角形晶体。具有相同取向的三角形晶体的生长是由于MoS2层和GaN之间的晶格失配较小。此外，合成的二硫化钼晶体和GaN晶片的界面质量的探索，通过X射线光电子能谱。用合成的MoS2层在GaN上制作异质结器件，显示出优异的整流二极管特性和光照射下的光伏作用。这项研究揭示了适合的含氨的ATM前体在CVD过程中生长的二硫化钼晶体GaN上，以获得合适的异质结构的设备应用。同样，考虑到MoS2层的催化活性，所开发的异质结构对于制氢的应用是重要的。

In this research, we proposed to develop molybdenum disulfide (MoS2) and gallium nitride (GaN) heterostructure for short wavelength photodetector applications. In this prospect, we have studied the van der Waal heteroepitaxial growth of MoS2 film by chemical vapor deposition (CVD) method on the GaN surface. Synthesis of MoS2 triangular crystals was achieved on Ga-terminated GaN substrate by the CVD technique using the ammonium tetrathiomolybdate precursor. Growth of triangular crystals on the GaN substrate surface with same orientation was obtained by the CVD process. The growth of triangular crystals with same orientation is due to less lattice mismatched between the MoS2 layer and GaN. Further, the interface quality of the as-synthesized MoS2 crystals and GaN wafer is explored by X-ray photoelectron spectroscopy. A heterojunction device is fabricated with the synthesized MoS2 layer on GaN, showing excellent rectifying diode characteristics and a photovoltaic action with light illumination. This study reveals the suitability of the ammonia-containing ATM precursor for the growth of MoS2 crystals on GaN in the CVD process to obtain a suitable heterostructure for device applications. Again, the developed heterostructure can be significant for application in hydrogen generation considering the catalytic activities of MoS2 layers.