Photoluminescence and magnetic properties of Mn-doped ZnS nanobelts

Zn_1-XMn_XS (X = 0, 0.02, 0.05, 0.09) nanobelts with significant room temperature ferromagnetism were synthesized via chemical vapor deposition method. X-ray diffraction and energy dispersive X-ray spectroscopy were used to confirm the successful doping of Mn²⁺ into ZnS nanobelts. Room temperature photoluminescence spectra of Zn_1-XMn_X S (X = 0, 0.02, 0.05, 0.09) nanobelts reveal that Mn concentration plays an important role in tuning emission color from orange to red. At low dopant concentration (2%), single nanobelt shows defect related emission of ZnS host and d-d (⁴T₁ → ⁶A₁) transition emission of Mn²⁺. However, only Mn²⁺ related emission is observed when dopant concentration reaches 5%. At higher doping, sideband (red emission band at 666 nm) to the red side of single Mn emission is detected, which may originate from the Mn-dimers. The red emission band has been observed for the first time in Mn-doped ZnS nanobelts. The enhancement of saturation magnetic moment was observed with increasing Mn doping concentration. These doped nanobelts with novel red emission band can find applications in the fabrication of magneto-optical nanodevices.