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

在这项研究中，我们提出了开发二硫化钼（MoS2）和氮化镓（GaN）异质结构用于短波长的光电探测器。为此，我们采用化学气相沉积（CVD）方法在GaN表面研究了MoS2薄膜的van der Waal异质外延生长。以四硫钼酸铵为前驱体，采用CVD技术在端ga的GaN衬底上合成了MoS2三角形晶体。用CVD法在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层与GaN之间的晶格不匹配较少。利用x射线光电子能谱分析了合成的MoS2晶体与GaN晶片的界面质量。利用合成的MoS2层在GaN上制备了异质结器件，具有优异的整流二极管特性和光照下的光伏作用。本研究揭示了含氨ATM前驱体在CVD工艺中在GaN上生长MoS2晶体以获得适合器件应用的异质结构的适宜性。同样，考虑到二硫化钼层的催化活性，发达的异质结构对制氢的应用具有重要意义。

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.