  We have grown germanium selenide (GeSe) triangular nanoplate arrays (TNAs)
with a high density (3.82E+6 / mm2) on the Si (111) substrate using a simple
thermal evaporation method. The thickness and trilateral lengths of a single
triangular nanoplate were statistically estimated by atomic force microscopy
(AFM) as 44 nm, 365 nm, 458 nm and 605 nm, respectively. Transmission electron
microscopy (TEM) images and X-ray diffraction (XRD) patterns show that the TNAs
were composed of single crystalline GeSe phase. The Se-related defects in the
lattice were also revealed by TEM images and Raman vibration modes. Unlike
previously reported GeSe compounds, the GeSe TNAs exhibited
temperature-dependent photoluminescence (PL). In addition, not previously
reported PL peak (1.25 eV) of the 44 nm thick TNAs at 5 K was in the gaps
between those of GeSe monolayers (1.5 nm) and thin films (400 nm), revealing a
close relationship between the PL peak and the thickness of GeSe. The
high-density structure and temperature-dependent PL of the TNAs on the Si
substrate may be useful for temperature controllable semiconductor nanodevices.
