Morphology-controlled synthesis and electron field emission properties of ZnSe nanowalls

ZnSe nanowalls are prepared on Zn substrates hydrothermally at 180 °C for 12 h. The structure, morphology, and chemical composition of the ZnSe nanowalls are determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDS), and Raman scattering. The concentration of hydrazine hydrate (N₂H₄·H₂O) plays an important role in the formation and morphology of the ZnSe nanowalls and XRD reveals that all the ZnSe nanocrystals have a cubic zinc blende structure. The ZnSe nanowalls with an optimal morphology deliver a good field electron emission performance with a turn-on field of 1.51 V μm⁻¹ and enhancement factor of 4797. The formation mechanism is discussed. The simple and controlled preparation procedures and good properties of the ZnSe nanowalls bode well for application in electronics and optoelectronics.